Racket for batting games



March 17, 1959 R. H. RoislNsoN 2,373,020

RAcxE'rs For: BATTING GAMES Filed Dec. 16, 1949 3 Sheets-Sheet J7A umM..

IN V EN TOR.

March 17, 1959 R. H. ROBINSON 2,878,020

RACKETS FOR BATTING GAMES Filed Dec. 16, 1949 5 Sheets-Sheet 2 Fi .14 21y? 44 4; 22 7 z 44 P17448 Z917 12 March 17, 1959 R. H. ROBINSON l2,878,020

` RAcKE'Ts FOR. BATTING GAMES Filed Dec. 16 1949 3 Sheets-Sheet 5 UnitedStates Patent fic 21,878,020 Patented Mar. 17, 19519 RACKEI FOR BATTINGGAMES Roy H. Robinson, Chicago, Ill. Application December 16, 1949,Serial No. 133,423y i 26 Claims. (Cl. 273-73) The purpose of theinvention is to provide an improved racket for tennis, badminton, squashand kindred t co-pending application No. 492,914, tiled June 30, 1943(which matured into Patent No. 2,593,714, issued April 22, 1952), asapplied to my racket frame construction. This application is acontinuation-in-part of my prior application Serial No. 492,914.

One of the primary objects of my invention is to provide means forresisting torque in racket frames and the torsional stresses set up byball impacts and particularly to resist such strains arising in a frameemploying my unique inturned arch disclosed in my aforesaid applicationSerial No. 545,630.

A further object is to provide special means for more effectivelyapplying my unique racket head shape, with its inturned arch, to thepopular laminated wood frame construction common to present-day racketconstruction, and makesame more effective. f n

A further purpose is to eliminate the deadness found in the outerportions of racket heads and so produce more equally resilient return ofthe ball from such points as compared with the central and lowerportions of the head.

A further objective is to enhance the resilience in my uniquelyfunctioning outer nturned arch construction and provide againstdelaminating stresses which 4are set up in and adjacent this arch,particularly in relation to laminated frames embodying wood and subjectto enlargement and distortion from atmospheric moisture absorption.

A further objective is to avoid the uneven distortion arising inorthodox wood frames from the dissimilar slotting required on theopposite sides of the head framing for the necessary protection of theStringing, resulting in one side of the head frame being weaker than theother, with unbalanced resistance to the heavy Stringing pressurecausing the frame eventually to warp to an unsymmetrical shape.

A further objective is to provide a new manner of laminating a frame andto better provide for stresses in all directions and more effectivelyhold the laminations together.

Further objectives are to simplify the manufacturing, minimize its costand introduce new materials into the frame and novelly dispose andcombine samekto great advantage and for new functional purposes.

With the above `and other objects in view, the invention consists ofcertain novel combinations h and arrangements of parts, the' relation ofwhich will be more thoroughly Z established in the following descriptionparticularly emphasizing and pointing out the same.

In the accompanying drawings:

Fig. 1 is a front elevation of a racket built in accordance with myinvention.

Fig. 2 is a side elevation of the racket of Fig. l.

Fig. 3 is a fragmentary diagrammatic View of the underside of the outerend of the frame of a racket having such a general shape as that of Fig.1 and indicating the approximate pattern of checking in the lacquerfinish resulting from stressing the frame in play.

Fig. 4 is a similar fragmentary diagrammatic view of the top side of thelower portion of the frame of Fig. 1, above the throat, likewiseindicating the stress pattern of the checking of the lacquer at thatpoint.

Fig. 5 is a diagrammatic side elevation of a racket frame indicating, inexaggerated form, the resultant shape of a frame of this type whendistorted by torsional stresses, when not properly built to resist same.

Fig. 6 is a diagrammatic side elevation showing the approximatearrangement of the grainlongitudinally -in wood reinforcements appliedto the frame in Fig. l.

Fig. 7 is a fragmentary plan view of a tubular reinforcement formingpart of a laminated frame, Fig. 1, with a portion cut away.

Fig. 8 is a fragmentary plan view of a strip of alternate reinforcementfor the frame of Fig. 1, with portions cut away.

Fig. 9 is a fragmentary plan view of reinforcement similar to that ofFig. 8 when made up in curved form to conform to the faces of the racketframe, and with portions cut away.

Fig. lO is a fragmentary plan view of a modified form of reinforcementin lieu of that of Fig. 8, and with portions cut away.

Fig. l1 is a diagrammatic frame cross section, indicating in principlethe cross sectional area of a normal laminated wood frame of orthodoxconstruction as compared with the reduced area made possible whenmodified to conform to applicants stronger frame construction, as inFig. 1, for example.

Fig. 12 is a fragmentary cross section-al perspective view of the frameof Fig. l, taken on line 12-12.

Fig. 12a is a perspective view of the throat wedge of the frame of Fig.1, and indicating the preferred grain A direction in each of itslaminations as made in glued 3- ply wood construction.

Fig. 12b is a fragmentary cross sectional view of the frame of Fig. l,taken at the throat on the line 12b-12b. Fig. 12C is a fragmentary crosssectional perspective View showing an alternate form of the frame ofFig. l2

with the overlay laminations having extending edges forming a protectivechannel for the strings and increasing frame strength.

Fig. 13 is a fragmentary plan view of the laminated face reinforcementson the opposite faces of the throat area, etc., of the frame of Fig. 1and with portions cut away.

Fig. 14 is a fragmentary enlarged front elevation of the outer end ofthe frame of Fig. 1, and with portions cut away.

Fig. 15 is a fragmentary plan view of the frame portion of Fig. 14, withportions cut away.

Fig. 16 is a sectional perspective view, taken on line 16-16 of Fig. 14,and with portions cut away.

Fig. 17 is a sectional perspective view, taken on the line 17 17 of Fig.14.

ment extending under the arch soit perspective view, taken on lineportions cut away.

Fig. 20 is a fragmentary front elevation of a modied form of the racketof Fig. l.

Fig. 21 is a perspective view of the reinforcing member adhesivelybonded to the soiiit of the arch at the outer end of the racket frameofFig. 20. i

Fig. 22 is a fragmentary plan view of the laminated face reinforcementforming the opposite faces of the frame of Fig. 20 in its lower portion,and with portions cut away.

Fig. 23 is a fragmentary plan view of a modified form of laminated facereinforcement similar to that of Figs. 13 and 22, and with portionscutaway.

Fig. 24 is a fragmentary sectional perspective view of a modified formof frame construction and particularly with reference to a modifiedmeans of string protection.

Fig. 25 is a fragmentary plan view of the outer string protective stripof the frame of Fig. 24 and the lay-out for the string slots at theouter extremity of the frame with particular 'reference to avoiding thecustomary frame distortion accompanying orthodox slotting.

Fig. 26 is a perspective View of a modified reinforcing member in lieuof that of Fig. 2l together with fragmentary portions of cantileverlamination frame construction adhesively bonded under same.

Fig. 27 is a front elevation of an alternative form of reinforcement forthe ends of my inturned arched frame and indicating its relation to theframe in dotted lines in connection with being adhesively bondedthereto.

Fig. 28 is a plan view of the reinforcement of Fig. 27 and in relationto said frame.

Figs. 29 and 30 are fragmentary front elevations of modified forms ofthe frame end similar to Fig. 14.

Figs. 31 to 42, inclusive are fragmentary sectional perspective views ofmodified forms of frame construction taken transversely of the frame, orperspective views (3l, 33 and 35) of assemblage of material preparatoryto press forming, and press forming indicated in Fig. 32 with sectionalperspective of frame section.

Fig. 43 is a plan view of a racket forming and integrating press for theframe of Fig. l and the like, with portions cut away and showing meansfor pre-stretching filament reinforcing.

Fig. 44 is a fragmentary cross sectional view of the press for shapingand adhesively bonding and compressing the outer opposed filament facelaminations on the pre-formed edgewise laminated core for the frame ofFig. l and the like, shown in cross section in the press. Referring indetail to the drawings, Figs. l and 2 represent a tennis racket formedwith my uniquely shaped head disclosed in my co-pending application,Serial No. 545,630, combining my acorn-shaped head with my inturned arch2 at its outer extremity. The racket has the width of its head at thisouter extremity narrowed in Yrelation toits broader base at the throatas formed by the sharply out-turning shoulders 3 of the frame, thisunique form being in distinct contrast to the conventional oval racketsnow in general use and having equally distinct advantages over samewhich have been emphasized in said co-pending application. In Figs. land 2, I have adapted this novelly shaped frame to the Wood laminatedframe construction in general use at the present time but with novelchanges in this laminatedconstruction itself which greatly improve itfor any of the present-day oval type rackets and still more particularlyfor my own novel head shape.

In studying the reaction in play of experimental rackets of this novelshape made up with ordinary laminated wood frames, I have made carefulexamination of the lacquer finish ou a frame to discover a definitepattern of checking in the lacquer after play which discloses importantfacts as regards the stressing affecting the frame and the resistancewhich should` be given the frame to best resist and resiliently react tosame. This pattern of checking, and so stressing, is diagrammaticallyindicated in Figs. 3 and 4. Fig. shows what is so regis-- tered on theinside of the frame at the outer extremity and Fig. 4 on the inside ofthe frame at the inner extremity, in approximate patterns, and inrelation to the central axis lines A-A and B-B respectively. One of theparticular purposes of my invention is to reinforce the racket frame inrelation to this checking pattern and with a counter pattern of hightensile-strength filaments which will cross the disclosed checks,preferably at approximately right angles thereto and so provide directresistance to these disclosed and so registered stresses which the framehas to meet, as proven by my check record.

A glance at the diagrammatic patterns of Figs. 3 and 4 will disclose thefact that the dominant stresses to be contended with are torsional, asproven by the checks being almost all diagonal 5, with only a few checks6 on the sofiit of the inturned arch 2 being at right angles to thelongitudinal axis of the frame 1a. It will be noted that the intensityof the stressing or the frequency of the check lines increasesapproaching the central axis of the head at the outer extremity and theinner extremity of same but that directly above the throat portion,approaching B-B from either side, these lines fade out, doubtless due tothe added strength of the solid throat. Other than that the torsionalchecking is registered with a much greater frequency and closeness 0flines 5 at the base of the head while as the sides of the head areapproached from the opposite extremities A--A and B-B, the check linesgrow less numerous, are spaced farther apart and practically disappearby the time the middle portion of the head is reached. In addition,longitudinal splits occur in the frame wood at the base of the head,as'indicated by lines 6a, indicating a tendency of the stressed frame toshear at this point, again indieating the necessity of diagonal shearreinforcement which I propose to meet with my diagonally disposedfilaments at these points of weakness and heavy stressing. It will beseen that ball impacts on the Stringing 7 tend to twist and turn theracket head inside-out, so to speak, with an inwardly revolvingmovement. It is to be particularly noted that in the present-daylaminated Wood racket frames no provision has been made against thisdominating stress, so proven by my checking patterns; that instead ofproviding diagonal reinforcement to resist this torque and shear, thegrain and fibers of wood laminations encircling the head, almost withoutexception, all extend longitudinally of the frame and in no case arethey arranged diagonally. My invention aims to correct this importantdeficiency in these laminated wood frames. Such provision is still moreimportant with regard to my uniquely shaped head with its inturned archas it will be found that if this head is not properly constructed tomeet the torque and twisting of the frame when tightly strung, it maytend to distort by twisting on its central longitudinal axis in thehead, as indicated in exaggerated form in Fig. 5. The frame of Fig. 1 isdesigned to avoid such distortion. It will also be understood that myinturned arch 2 is likewise designed to prevent the elongationdifficulty long presented by pres'ent oval heads. The heavy pressure ofthe transverse strings as well as that occasioned by the enlargement ofthe head with moisture absorption cause the outward pointing end ofthese oval heads to distort or collapse outward with the attendantnarrowing and elongating of the head. This is resisted by a few centrallongitudinal strings which become stretched and overstressed in thisbadly balanced construction found in all oval type rackets. In contrastmy inturned arch 2 brings these elongating pressures to a dead centerand tends to spring inward instead. With the highly resilient propertiesand resistance to set which I build into this arch 2, as will bedetailed, it is combined with the very taut Stringing rmly anchoredthereto to shoot the ball in T returning same. This, it will be seen,results from the arch bending slightly inwardly with the ball impact onlthe strings, then instantly and violently rebounding outward, thisoccurring coincidently with inward and outward action on the part of theout-turned side arches 4. In this action, the ball must linger slightlylonger on the strings as they are drawn across same in stroking, soputting more st or spin on the ball. In an oval head, on the contrary,the out-turned end arch fights against the two out-turned side archeswith ball impact on the strings, tending to neutralize same and preventthe bow action of applicants novel frame, just described.

A further fault common to tennis rackets in general, to whichthisinvention is further directed, is a weakness or deadness with ballreturns from the outer portions of the head. As contrasted to a soundand strong return of the ball from the central and lower portions of thehead, a weaker or dead return will often be felt on returns from pointsfurther out. To provide against this deadness in the outer portion ofthe racket and also further provide means for resisting torque and thetwisting movements suggested in Fig. 5, including cross-bonding thelongitudinally disposed laminations of the frame, I novelly providemembers 9 of Fig. 1, which are adhesively bonded on the opposite facesof the frame. The

position of these members 9 may be varied to some de-l gree, upward ordownward of the frame as may be found most effective for any frame, butthese members are so located as to strengthen the outer portions of thehead frame by trussing same out to a greater thickness,

' the members 9 being tapered to a thick belly in the central portion asnoted. They may be formed of any suitable material or combination ofmaterials, wood, plastic, filaments, etc. In the present instance,however, I make these of wood, cut and shaped so that, asdiagrammatically indicated in Fig. 6, the grain and wood fibers extenduncut along the full outer length thereof or at least approximate such apurpose so far as the shaping makes feasible. This can be roughlyaccomplished by cutting the wood while in bent position or bending sameto a at gluing back after cutting the back to a curved or angular line,etc. The members can be bent, as with steaming, to the curving outlinesof the head, and should be, to keep the grain extending longitudinallyand continuously for tensile strength. These members 9, it

will also be understood, can be advantageously applied to any oval orother wood frame as well as to my novel frame of Fig. l and the like.

When desired, as in the case of Fig. 1, I also reinforce the inturnedarch 2 and the adjacent outturned arches 8 with similarly imposedoverlay laminations 11 bonded on the opposite faces of the frame, aswill be more clearly illustrated in Fig. 14. With moldable mate` rials,such as plastic and the like, these reinforcements 9 and 11 can bepre-formed to the exact shape of the racket frame. In some cases themembers 9 and 11 may be formed and applied as and in one continuouspiece, extending from one side ycontinuously about the end of the frameto the other side. In molded material, this is a simple matter. Withwood or stamped material, however, combinations of forming or waste ofmaterial may make this less desirable.

In addition to the above, the frame of Fig. l, and as a notable featureof this invention, departs radically from standard laminated wood racketconstruction as practiced. It will be understood that in the latter casethe frame is formed of a multiple ply of wood laminations bondedtogether edgewise to the plane of the Stringing except for somereinforcement generally added at the base of the head. The woodlaminations have their grain extending lengthwise of the frame, exceptin rare cases, and are cut and finished to form the complete thicknessof the head frame (measured at right angles to the plane of theStringing) except so far as the portion adjacent the throat isconcerned. By contrast, in my construction I cut the bonded woodlaminations forming the frame to a thickness much less than 'itiA theaforesaid as well as much less than the final thickness of the frameabout the head. I then build the head frame thickness up by bonding facelaminations extending around the head as a Whole or for the most part,disposed crosswise of the edgewise laminations, and so at an anglethereto, and on the opposite faces of the edgewise formed frame. Thisnovel racket frame construction, with the wood and other laminations inthe two distinctly different planes, provides great advantage instrength after the manner of a box girder so to speak, and particularlyfor resisting the bending stresses applied at right angles to the planeof the Stringing and at the same time the tremendous pull of the hightensioned Stringing in the plane of the Stringing while at the same timestrongly bonding the wood laminations together across theirlongitudinally disposed joints to resist delaminations, longitudinalshear, and the notable torsion already discussed. Also, because of theseedgewise and thus core laminations being cut much thinner for the frame,as noted, it will be seen that where laminated frames are made inmultiple by the well known lblock method where the veneer laminationsare made up in a formed block and the block then sawed into a multipleof individual frames, a correspondingly greater number of frames will beobtained from each such block because of this reduced thickness of theframe with regard to these edgewise laminations. Similarly, with theother method of making up frames individually, correspondingly narrowerstrips of wood or veneer are made possible for the work.

In forming the frame of Fig. 1 with this novel construction I alsoemploy novel laminations for these crosswise or face laminationsencircling the head, while these laminations can also be made of Woodwhich is bent by steaming methods to the shape of the head and thensliced up to the proper veneer thicknesses, or of various othermaterials and such as are moldable to the shape, as plastics, etc., Iprovide still more unique laminations, particularly designed to meet,among other things, the shear, torsion and twist disclosed in connectionwith Figs. 3, 4 and 5. For this purpose I employ a braided tube 13,formed with high tensile-strength filaments of glass which are coatedwith adhesive, the tube being filled with other glass filaments 14,preferably continuous throughout the length of the tube, and similarlycoated with adhesive. These filled tubesform the lamination 12, Fig. 7.The laminations 12 are applied to the opposed faces of the edgewise woodlaminations ofthe frame, which have been previously glued up, and whilethe adhesive coating on the glass filaments is in an uncured state, andare then mol-ded to same under pressure as shown in Fig. l2 andelsewhere. It should be particularly noted that the filled tubelaminations in the unhardened state are thoroughly pliable and becauseof the diagonal disposition of the tube filaments are readily and freelyadapted to the shape of the frame at any and all points and can be givenvaried widths and thicknesses at different points of the frame as de`sired, the loose filaments 14 filling the tube being also free to adjustthemselves readily to such changing form at any point. It will be seenthat because of the diagonal orientation of the tube filaments I alsoprovidel high tensile-strength diagonal reinforcements about the frameto counter and resist the torsional and shearing strains already sofully explained. At the same time the continuous longitudinal filaments14 providethe strong reinforcement and resilience, longitudinally of theframe, for resisting the various bending stresses to which the frame issubjected.

When the reinforcing members 9 and/ or 11 are included, as in Fig. l,the face laminations 12 are molded directly over and to same. Where suchis the case, the high tensile-strength filaments 14 are so strutted outfrom the frame ycore edgewise laminations at such points, therebylprovidingexceptionally increased strength to resistthe bending stresses,eliminate deadness and greatly enhance the resilience of the frame andthe inturned arch 2. When the members 9 and/or 11 are not included, thelaminations 12 are molded vdirectly to the edgewise core laminations atsuch points and the others where intermediate insertions are notincluded. The lamination 12 has its opposite ends either abutted 13 atthe throat on the central axis B-B or overlapped so that the ends extendany desired distance on the opposite sides thereof to further reinforcethe frame at this point as may be preferred. Alternately the joint maybe made on the arch 2 if the ends are there overlapped in symmetricalrelation to the axis A-A so as to reinforce the frame end on the arch 2.

Figs. 8 and 9 show alternate uses of the tubular laminations 12 by firstcombining same with a facing or facings to which they are adhesivelybonded to provide a preformed unit, the straight unit being 1S and thecurving one, Vfollowing the outline of the racket head, being 16. Thefacing laminations, 17 and 18, and 19 and 2t), may be of any suitablematerial but in this instance I employ vulcanized bre or fish paperwhich is strongly bonded with preferably a thermosetting adhesive suchas Bakelite or phenol-formaldehyde in a press under heat and pressure asrequired. This sheet fibre can be of any desired thickness and color.lts outer surface, after the strips are finally bonded, providesexcellent bonding surfaces for further gluing, whereas the hard glassysurface of the nally formed and hardened unit 12, if used by itself,presents a more dificult and uncertain gluing surface when bonding samelater with other laminations or portions of a racket assemblage. This isimportant Where rackets are made in shops not employing hot press ortheir equivalent means for bonding and` where it facilitates assemblageand production to employ the glass filament reinforcement in a formalready made up, as with 15 and 16, secure much higher pressures inbonding same, and be sure of a safe bond throughout between the glasselements and the wood laminations.

When such substitution is made for the face laminations 12 of Fig. l,using the lamination 16 of Fig. 9, the strips of fibre or face material2t) and 19 are stamped or cut o'ut to follow the contour of the rackethead as indicated. To avoid Waste, in stamping out the fibre for thispurpose, spaced apart joints as 19a and 2da can be made, these beingstaggered in relation to each other in bonding, the unit 12, however,forming a continuous member in the sandwich so formed. After finalbonding in a press in which the elements 2t), 12 and 19 are assembled insuperimposed relation, the complete preformed element 16 is glued oradhesively bonded-in duplicateone on each of the opposed faces of theedgewise laminated framecore of the racket head and in lieu of thelaminations 12 in Fig. 1, this being accomplished in a suitably shapedhead form and subsequent to the edgewise core having first been glued upand surfaced for properly bonding to these laminations 16 (after themanner of Fig. 44).

Fig. shows an alternate form of laminated unit 21 which can be used whendesired in place of or 12 of Figs. 8 and 7, respectively. In this casesheets of vulcanized fibre or other suitable material are adhesivelybonded together with glass fibre or other high tensilestrength filamentsinterposed, as shown. In this way both longitudinal and diagonallydisposed tensile reinforcement is procured without the braided tube 13of Figs. 7 and 8. It should be understood that it has not been foundfeasible to Weave glass filaments in a diagonal or braided weave exceptin tube form. In lieu thereof, I dispose rectangularly woven glass clothdiagonally, as 23, in the sheet assemblage and longitudinally orientatedfilaments in-unwoven or woven form, as 25, between the fibre sheets 21a,2lb and 21C. The glass filaments throughout are coated with preferablythermosetting adhesive, which is likewise the case withregard tosFigs.7, 8 and9, and the laminated sheet' assemblage finally cured and wellbonded under pressure, to which high pressure hydraulic presses arevwell adapted, the same as in making the vulcanized sheet fibre itself.Thereafter this laminated stock can be stamped out tov form the stripsof Fig. 10 with excellent exterior bonding surfaces for gluing same inan assemblage with the wood laminations of the racket frame.

The edgewise laminated core construction of the frame of Fig. l isdisclosed in Fig. l2 and subsequent Figs. 16, 17 and 18. While othermaterials may be used in lieu thereof, l make the core laminations, inthis instance, as shown in Fig. l2 (21d, 22, 23, 24, 25 and 26) ofselected woods or a combination of different woods. Any desired numberof laminations may, of course be ernployed. The tensile reinforcement 12is interposed in the assemblage between the wood laminations 21d-22 and25-26, respectively, as indicated. While other highstrength fibers maybe used in my tensile filaments in Figs. 7-10, etc., the glass filamentsare much preferred because of their very remarkable properties and highstrength-weight ratio aswell as their immunity to moisture absorptionand their dimensional stability. As the glass is itself an abrasivematerial, I overlay the glass laminations 12 with protective wood layers21d and 26 where the Stringing 7 may have a direct bearing under hightension on the edges of the Stringing holes 7a, at the same time placingthe glass reinforcement 12 as close as possible to the outer surfaces ofthe framing to provide a maximum of stress resistance in the frame crosssection. These outer laminations 21d and 26 are of strong selected hardwood, such as second growth white ash or hickory. rfhe inner'laminations22--25, however, being as they are, housed in on the four sides of theframe section by the strong glass laminations 12, are preferably of woodof lower density so as to so offset the higher specific gravity of theglass elements. It should be understood that the inner face lamination15 is the inlay reinforcement occurring only at the throat and extendingup the sides of the head framing for a desired distance, as indicated inFig. l, and above that point the lamination 26 is the outside and stringbearing face for the inside of the frame. 15 is in itself a multiple plyof 17, 12 and 13 as shown in Fig. 8 and with its diagonal glassfilaments of 12 pro-- vides this additional strong resistance to thetorsion stresses and shearing at the throat end of the head disclosed inFig. 4 as indicated by 5' and 6a. The other two edgewise laminations 12further provide against this torque at this point and throughout theframe, extending as they do, continuously about the head and down thehandle, except in modified forms where, when dictated by weight, or costconsiderations, etc., portions of same may be omitted. I make sucharrangements by retaining the elements 12 at the outer end of the headonly, along with 15 at the inner end of the head, thereby providingtorsional resistance at the heavily stressed areas of Figs. 3 and 4;- orI may extend the inner lamination 12, next to 26, merely around the headportion and not down the shaft While omitting the outer lamination 12,next to 21a', or retaining same only at the outer end of the frame toreinforce the arches 8-2-8 and adjacent thereto. Other similarmodifications may be made to provide different models, weights, balancesetc., as may be preferred.

After the edgewise laminations of the frame are assembled, formed andadhesively bonded together along with the throat wedge 27, whether byforming frames individually or sawing or slicing same from a glued blockassemblage, the edge faces are sanded, if necessary and prepared forbonding with the face laminations 12 which are adhesively molded to theopposite faces of same. The edges of the outer laminations, as 21 and15, or 26 as the case may be at certain points of the frame, are first,however beveled 28, or rabbetted, so that in the molded bonding andfinal shaping of the face laminations 12, the latter will have theiredges extended and formedvabout the edges ofthe edgewise laminated coreunit. The latter will so be firmly gripped and bonded against laterdelamination, not only by the stresses of stringing and play butlikewise and particularly from moisture absorption and expansion, itbeing noted that the glass filaments so gripping the wood laminationsand across their ply joints are unaffected by this moisture.

In order to protect the Stringing exposed on the outer rim of the rackethead against abrasion and injury from ground strokes, etc., as is foundnecessary in tennis rackets, I further novelly mold these cross or facelaminations 12 so that around the outer half of the head, or for adesired distance, the edges of 12 are protruded outward on the outeredge of the frame, as 12a of Fig. l2c so as to thereby form a recessedgroove in which the Stringing 7 lies and is properly protected. Thisarrangement is important for an oval frame but is still more importantfor the frame of Fig. 1 with its inturned arch 2 in preventingunbalanced distortion in the tightly strung racket head. In the ordinarywood frames, which are of oval type, the aforesaid string protection isprovided by cutting in sinkage slots where the Stringing lies on theface of the outer rim. In Stringing a racket these slots have to bedifferent on the opposite sides of the head with respect to the centralaxis and as they are cut diagonally across the grain, as is well known,they weaken the frame and to different degrees on these opposite sides,thus causing the frame in its unbalanced and non-symmetrical conditionto tend to warp outward on the weakened side or corner of the frame, asthe frame ages. In the frame of Fig. 1, the warping action is different,as suggested by Fig. 5, and so it is of prime importance to eliminatethis present un-balance found in orthodox frames, the more particularlyin the frame of this invention. This is facilely accomplished by themolding of the laminations 12 which is further disclosed in Figs. 14-18.Attention should also be called to the fact that in those portions ofthe head where the element 15 is employed, as in Fig. 12, its outer facemember 17 protects the Stringing from direct abrasive bearing on theinner glass iilament member 12 of same where the Stringing holes occur.

In Fig. 11 is indicated diagrammatically the manner in which the crosssectional area of the frame is reduced by my construction so as togreatly reduce air resistance in hitting with the racket. This is madepossible by the use of the laminations 12 which are many times thestrength of wood laminations as used in orthodox Wood rackets, the glassfilaments, 13 and 14 of 12 (as indicated in Fig. 7), having strengthsranging between 100,000 and 200,000 p. s. i., as compared with mediumsteel at 50,000 p. s. i. and wood with but a fraction of such tensilestrength. Thus, if the normal cross sectional dimensions of the orthodoxwood frame are represented by 29 and 30, the edgewise thickness of thelaminations, as 29, is reduced to the thickness 31. To this core is thenadded the two relatively thin face laminations 12, thus giving a totaliinished thickness of only 32 which is substantially less than theorthodox 29. Similarly, with the inclusion of the laminations 12 in theedgewise assemblage, the normal face Width of the orthodox frameindicated as 30, is reduced to 33 by reason of the much greater strengthof the edgewise disposed fiberglas laminations 12. It will be understoodthat while the designation fiberglas employed in the specificationrefers to the trade-marked material known as Fiberglas, conventionalfiber glass, or glass iiber material forming glass threads or the like,now widely manufactured, may be used. Fig. 11 is intended todiagrammatically disclose the above in principle, only, and notnecessarily in exact dimensions.

The inner lamination 26, which is a very important one in developing mynovel and maximum resilience in the frame and my induced reactions toball impacts, serves in the compression capacity of cantileversterminating on either side of and adjacent the sollit of the arch 2which in its functioning performs high tensile duties. Lamination 26 maybe glued up with the other edgewise laminations 12-21 and designed toextend with same down the full length of the racket frame to the handletermination. However, in this instance, and particularly to stillfurther enhance the resilient reaction, I merely extend 26 as ahoop-like inner rim around the inside of the head, instead of down thehandle shaft. This also has the advantage of permitting the use ofshorter and often more eX- pensive material and particularly material orchoice woods which are only available in shorter lengths or can be hadeconomically only from short Waste or scrap. Yew and Osage Orange woodare such materials of highly resilient properties but very expensive inlonger lengths of good quality. Further advantage of this can be takenby jointing the rim 26 on axis B-B at the throat, otherwise it can beextended around the head in one piece. High compression plastic is alsoa particularly desirable material for 26. 26 can be, and in this case ofFig. l, is further reinforced by the inlay lamination 15, of Fig. 8,glued to the outer face of same, as shown, in the lower portion of thehead. In this instance, 26 and 15 may be glued into the head frame afterthe edgewise laminations and the throat wedge 27 have first been gluedtogether, all at one and the same time, and before the crossWiselaminations 12 are bonded on this edgewise core. Also all the edgewiselaminations, including 26, along with the two opposed face laminations12 may be glued together in a single simultaneous gluing operation. Avery important feature of the gluing in of 26, together with 15, is thatthe head frame is rst distorted outward at-the sides as C-C and the endas D by applied force, as indicated by the direction arrows at thosepoints, and to the proper predetermined degree. 26 may be pre-shaped aswith steaming in the case of Wood, but in any case its upper endspreferably extend outward so as to require pressing or snapping inwardper arrow E in placing same Within the distorted frame for the gluing ofsame and likewise 15. After the glue is thoroughly set, the distortingpressure on the frame at C-C and D is removed and the frame allowed toretract toward its normal position. In this way the wood laminations ofthe frame core assume normal position or approach to same with littlefiber stress While 26 and 15 coincidentally become pre-stressed andcompressed so as to be highly sensitive, resistant and reactive todistortion of the frame inward at C--Cl and D as results when the ballimpacts on the Stringing in play. This is particularly important inconnection with the cantilever ends of 26 which are designed toresiliently resist the depression of arch 2 with the ball impact, andwith the aforesaid pre-setting, and kick upward violently in reaction tothis bending and compressing impact, and in supplementing unison withthe tension reaction of the arch 2. A resilient plastic of highcompression strength is accordingly a preferred material for 26 and thesamey for the laminations 17 and 18 of the unit 15. The lamination 12 towhich 26 is glued should preferably be provided with a thin fibrefacing, 12 in Fig. 12, when the edgewise core is first glued up so as toprovide a good gluing surface for bonding 26 to. When 26 is alternatelyextended down the handle shaft instead, however, and is so glued upsimultaneously with the other edgewise core laminations, this fibrefacing 12 can be omitted. It should also be noted that the cross facinglaminations 12 which are glued on the edgewise formed core frame asalready noted, are also preferably so glued in place when the frame isslightly expanded outward at D with 26 so bonded in place until thebonding of the faces 12 is fully set and the frame then released. Inthis way these liberglas faces remain likewise preset to give greaterresistance and spring action to the 8-2-8 arch structure and with lessiiber strain on the weaker wood laminations of the frame core with theinward bending of the arch 2. Also it should be noted that in lighter orsimpler frames, the lamination 26 may be formed with the structure of 15(Fig. 8) and 15 omitted if desired from the frame of Fig. 1 where itforms the lower inlay reinforcement'of'the' head frame, 26, alone, soserving in a dual capacity. The outer cantilever ends of 26 which havebeen glued in whilethe frame end has been temporarily distorted outwardat D, and so compressed inward with the removal of this distortingforce, are subsequently forced still further inward by forcing the arch2 slightly inward at D in conjunction with my preferred method ofstn'nging the frame as brought out in my pending application Ser. No.545,630 already referred to. In this way both the arch 2 and thecantilevers 26 are pre-set and loaded to give the ball return a maximumkick Other features which will be later brought out still furtherenhance this.

Continuing with regard to the construction of the throat and lowerportion of the frame of Fig. 1, the V- like -throat portion between theframe members on opposite sides may be formed with a solid wedge fillingsame in the customary manner. In this instance, however, I prefer tolighten the head at this point, lower the balance and produce greaterWhip and resiliency by gluing in the uniquely shaped wedge 27 as shownin Figs. 1, 12a and 12b. This novel wedge provides a strong and readilyglued bearing between the opposed frame members, yet still leaves ahollow V portion 34 inside the throat in its lower portion. This chamber34 is covered over by the face plate-like members 35 which extend upover 27 to which they are glued along with the frame members and taperoff on both sides under the face laminations 12. The face laminations12, in turn, have their abutting or overlapping ends at the throatoutwardly covered by a cover and reinforcing lamination 36 formed ofvulcanized iibre or other suitable material, when desired, which furtherreinforces the base of the head against the torsional twisting inward ofthe frame to which rackets are prone. Where greater shaft strength isdesired, the thin reinforcing face plates 35 can extend down same toterminate at the end of the handle but in this instance l terminate samewith the V-shaped end 35 below the throat as shown, thereby economizingin this more expensive material, reducing weight and providing a furtherbending and stress relieving area below same and between it and thetapering handle forming overlay 1c above the handle 1d. The intermediateand so exposed frame Shanks 1b have the strut wedge 38 between them andthis can be made of mahogany or other suitably ornamental wood. Anornamental and structural holding band 37, of suitable material, ispreferably added at the base of the throat. The plates 35 areconstructed to put extra resilience and strength into the throat areaand are preformed preferably of 3 ply as shown in Fig. 13. The outerface is av thin layer 35a of strong resilient plastic of highcompression strength; the inner core 35b is fiberglass in one or moreply and preferably with filaments extending vertically and horizontallyeither in woven cloth or unwoven formation, all of course coated withthe customary adhesive; the inside lamination 35C, of the ply, is alsoplastic like 35a but thinner, preferably, to minimize Weight andprovides a good outer gluing surface for bonding to the frame to whichit is adhesively bonded. Other materials may be alternately used foreither or both 35a and 35C, as for example vulcanized paper or sh paper,and for 35h high tensile-strength nylon or fortisan laments for theglass bers. When desired, the outer member 35a may be omitted and thetiberglas, which in its hardened adhesive matrix is quite ornamental,made the exposed outer face. lt will be understood that the preformedplates 35 are normally cut from mass production sheets formed under heatand high pressure with hydraulic presses giving same great strength notso attainable in shop gluing, yet providing good gluing surfaces forincorporation in the racket frame which a liberglas matrix itself, whenpreformed, does not so readily or securely provide.

In. view of the greater strength presented by the strongly shaped baseformed by my acorn-shaped head,

as compared with the orthodox oval type rackets, and particularly whenformed as herein with my liberglas construction, I furthermore, whengreater whip is desired, graduate the thickness of frame about thethroat by sanding it down prior to gluing on the plates 35', reducingsame to a minimum thickness at the point 39, as indicated in somewhatexaggerated form in Fig. 2, from the upper points adjacent the ends of36 and from the lower point adjacent the band 37 (Fig. 1). Alternatelyand in lieu of this, the plates 35 themselves may be provided withgraduated thickness to accomplish a similar end and the frame Shanks of1a, in such case, left without graduated thickness at this point. l alsopreferably provide a holding tie 39 of glass fiber cord or filamentswith adhesive coating, molded to and about the throat at the thinnestpoint or area 39, as shown, under the heat and pressure required forpolymerizing. This provides a still greater holding strength at thishinge point for the plates 35 against the bending moments developed inhitting the ball and so still further augments the resilient reaction ofthe plates thereto.

Figures 14 to 19 show in larger scale the construction of the outerextremity of the racket head of the Figs. 1 and 2, and particularly withregard to the vitally important arches 8 2-8. It will be noted, Fig. 14,that the outturned arches 8 formed in conjunction with the inturned arch2 are widened in face depth and so strengthened by insert members 46glued in the laminated frame construction and formed of strongcompression material either wood or suitable plastic composition. On thesoflit of these arches 8 and abutting the sot of arch 2, the cantileverand compression lamination 26 ends to permit the high tensile-strengthglass lilaments of the tensile lamination 12 to take over and providethe vital spring soint of the inturned arch 2 and resist with theirunique physical properties and superstrength, the tremendous breakingstresses centered on this point. While other strong iibers such asnylon, Fortisan, etc., may be employed, none of these provide all theessentials or an equal strength. Of vital importance is the fact thatthe glass filaments will not take a set, or stretch, creep, or fatigue,substantially, nor absorb moisture and change size and length thereby.All of these requirements are needed for the proper and permanentfunctioning of the spring arch 2 in its tensioning reaction andresistance to the very great string pressures brought to bear on it, andit must not take a 5st, as does Wood by itself. To better meet itsduties, the berglas soit lamination 12 of arch 2 is preferablyreinforced with additional glass filaments extending through the arches8-2-8. These are shown in Fig. 19 as unidirectional longitudinallydisposed layers 41 and 42, stitched 43, or otherwise secured, on to theiberglas braided tube 13. Unidirectional or equivalent woven berglastape or cloth can also be used for 41 and 42 as dictated by convenience.As shown in Fig. 12, etc., the frame face laminations 12, in beingmolded on the edgewise core laminations of the frame, have their readilyadjustable and changeable shape broadened or narrowed at the differentpoints, and with corresponding and resultant changes in thickness. Fulladvantage is taken of this to provide the frame with changing structureat different points to meet its changing stresses, functions and dutiesat the different points. Thus on the arches 8 which are severelystressed in conjunction with the bending action of the inturned arch 2,or by any enlargement of the frame from moisture absorption, thewidening of the face laminations 12 greatly strengthens same andcoincidently the so extended and projected edges 12a form a protectivechannel for the Stringing 7 (Figs. 16-18) for preventing abrasion ofsame from ground strokes etc., at the outer portions of the head. Midwaydown the frame this protection being no longer required, 12 is then keptush with the vresistance to the heavy Aby the so broadened cantileverarches 8.

vasr'spec frame on the outer side and instead extended inwardly to coverthe extra thickness of the added lamination 15 from thereon down (Figs.1 and 12). In presentday wood frames, the Stringing lacking theprotection here provided by 12, has to be sunk in slots in the wood`whlch not only weaken the frame by cutting diagonally lacross thelongitudinal wood fibers but also cause it to distort as the slottingchannels have to be different on the opposite sides of the frame and sooffer unbalanced pressure of the Stringing which calls for 50 to 70pounds pressure on each string, As shown in Figs. 14 and 16, the shapeof the inturned arch 2, itself, provides protection for the strings atthe central portion thereof so 12 in its molding is accordinglygradually brought fiush again with the frame on the outer side andcorrespondingly thickened so as to so strengthen the arch where theframe becomes narrower at this point as shown in Figs. 14 and 15. Thearch 2 is so given more :dexibility by thinning, yet its strength somaintained, and it is staunchly supported at its ends These arches 8-2-8preferably have their heavily stressed laminations tied together and arefurther reinforced by bands yor wrappings 44, formed of adhesive coatedglass filaments molded on the frame under heat and pressure andpreferably after the frame is already glued up. vThese reinforcings 44are preferably located so as to l'come between the strings as shown inFigs. 14-15 so as not to interfere with same when possible and wherespanning the sunken channel formed by the edges 12a rest on cross fillerblocks 45 glued in with same and further cross bracing the frame and12a. As the glass filaments are immune to water absorption, these crossbands 44 hold the wood laminations together and against strongdelaminating tendencies at these points both from the play action ofthis unique frame and the wood swelling in moist weather. As furthershown, Fig. 15, the arches 8 2-8 are further strengthened, in additionto the face laminations 12, by the reinforcing cross laminations 11,spanning the edgewise laminations and graduated to increased thicknessat the center of arch 2 to strengthen same. This also provides specialresistance to the twisting stresses met with in the frame as indicatedin Fig. 5.

A particularly important feature of Figs. 1 and 14 is the positioning ofthe edgewise lamination 12 so that it forms the soffit of the heavilytensioned arch 2 on its tension side, then turns upward on either sideto effect a more Vertical and so more effective tensile resistance bythe glass filaments and then continues on to reinforce the cantilevers26 and fillers 40 on the upper or tension side thereof. Correspondinglythe other and upper lamination 12 cornes in the upper portions of thearches 8 to so reinforce same on their tension side and is anchored downby the centrally placed bands 44 in the sinkage of arch 2 so as todevelop a maximum resistance to the tension stresses in the top of theheavily stressed arches 8. The lower lamination 12, in its turningupward from the sofiit of 2 also provides resistance to shear stressesdeveloping in such a span. I further enhance the resilience and strengthof arch 2 and avoid over-stressing the wood fibers therein by throwingthe tension load in the arches 8-2-8, and 2 in particular, largely onthe strong tensile laminations 12 or their equivalents. Toward this end,I preferably pre-shape, as with the customary steaming process, theedgewise wood laminations, as 21d (Fig. 12), to the shape of the rackethead, or the arches 8-2-8, or in any case the inturned arch 2, prior togluing same together. I further, preferably, then, in conjunction withassembling these laminations in the press-form, properly prepared forgluing together and with the other laminations as the tensile edgewiselaminations 12 and also 26 when desired, force the sofiit of thematerial at arch 2 slightly ,outward of the head D (Fig. 1) or asindicated in some- "14 what diagrammatic and exaggerated form as 52' inFig. 20, and in this temporarily outwardly tensed position glue theassemblage permanently together before removing same from the form.Thereupon, the preshaped laminations tend to return to their formerdeflection in arch 2. Thereafter, as already noted, I preferably forcearch 2 slightly further inward of the head in conjunction with theStringing of the racket and firmly anchoring Stringing under hightension thereto. This all results in bringing the strong tensionmembers, as 12, into resilient action while not over-stressing theweaker wood fibers. It has been found that the glass filaments in alaminated structure can develop a tensile strength of 120,000 p. s. i.with a stretch of only 3%. It is the quick recovery of arch 2, as withthis stretched tensile reinforcement which drives the ball the harderand faster. In this connection it may be noted that the diagonallydisposed filaments of the braided casing 13 (Fig. 7) of 12 form a stressdistributing intermediary tending to spread over a larger wood area, andgradually,

the direct pull of the longitudinal filaments 14 in action and therebyreduce fatigue and rupture in the wood bers to which 12 is glued andwhich are required to work with the non-stretching glass filaments ofmuch greater resistance, etc. The same tensioning and removal of slackin filaments 14 of upper edgewise lamination 12 similarly tensions thearches 8 to their supplementing action with inturned arch 2. Furthertensioning is provided for as will be noted in connection with Fig. 43.In cheaper rackets the above pre-steam-shaping can be omitted, andinstead the wood laminations can be bent and glued together to theracket shape and forming the arch 2, and, thereafter, the tensilelaminations, as 12, glued to said Wood laminations while the so-forrnedarch 2 is temporarily distorted outward of the head.

A further means of developing the tensile and quick spring action in the8--2-8 arches of my frame is shown in Figs. 20 and 21. Fig. 20 is amodified form of the racket of Fig. 1 and has a special reinforcement 46adhesively and mechanically bonded to the inner side of the arches 8 2-8to form a strong spring-like kicker to still further accelerate the ballreturn by this resilient arch structure. The element 46 is preferablyformed with a backing 47 of highly resilient plastic with highcompressive strength which is molded or adhesively bonded to a tensilelamination 48 of glass filaments and with a facing .49 likewise ofresilient high compression plastic, all said members being wellintegrated by proper bonding. These elements 46 can be formed asindividual units with mass molding techniques or can be produced insheet form from which the units are stamped or cut. The hightensile-strength reinforcement 48 is formed as 12 of Fig. 7 withlongitudinally extending filaments or can be unidirectional cloth orequivalent, particularly if 46 is produced in multiple sheet form. Theiiberglas wall 48 is importantly shaped and, similarly to the bottomlamination 12 of Fig. 14, it dips from the upper portion of the two sideoutturned arches (as 8) downward to the bottom of the central inturnedarch (as 2). Each of the three arches is so provided as shown with athicker plastic wall on its compression side. 46 is formed in itsinitial shape, whether by molding or/and machining or otherwise, to thedotted outline 5t) with the tail ends 51 extending widely outward andthe central arch less depressed downward than in its final shape, asshown. After the racket frame 1 is formed with the arch structure 8-2-8,the inturned arch 2 is pressed slightly outward as indicated by thedotted lines 52 of Fig. 20 so as to conform to the more flattened topform 52 of 46 except with regard to the extending ends of tails 51. 46is then firmly glued under pressure to the soiiit of the arches 8 2-8 inconjunction with which the wider extending tails 51 are forced inward soas to come within and press hard in compressed position against thesides of the frame 1. These tails are preferably formed with small sharpstuds or spike points 51a which press into the frame and bondmechanically therewith in addition to the gluing. If the framecontracts, as with ball impact on the strings, the tails undercompression so anchor and hold 46 in place all the more securely, soinsuring it from being loosened. After the gluing has sul'liciently set,the temporarily applied outward pressure is removed from the arch 2 andthe frame and 46 allowed to press back toward normal position again andso that 4S of 46 is forced into tension and the slack removed while thewood iibers of 2 remain substantially unstressed or as originally formedor approaching same, 46 accordingly assuming something of its final formof Fig. 21. When the racket is subsequently strung under strongpressure, the arch 2 is preferably forced, in conjunction therewith, toa slightly deeper inward curve and so tensioned or cocked to receive andreturn the ball impacting on the strings. By reason of the aforesaidprocedure the weaker or wood laminations of the arch in such inalposition have their liber stress kept within safe limitations while themuch stronger glass libers forming the tension member in the bottom ofthe arch (they may be covered with a thin iilm of the plastic bottom 49if desired) are given a much higher but still safe stress for them toprovide the quick recovery and spring action required of the arch whichis further accelerated by the action of the compressed tails 51 forcedfurther inward of the head by the sides of the frame which contractmomentarily inward with the ball pull on the cross Stringing. In thisaction, it will be seen that the spring reinforcement 48 of the two nextarches (as 3) is forced inward from both ends so contracting thesearches each to a smaller radius, as in winding and so tensioning a clockspring. This produces a violent expanding reaction along with that ofthe inner arch portion (as 2) following the ball impact on theStringing.

When desired and to reinforce still further the arches 8 on theirtension side, i. e. the top or outer side, I also bond the tensilereinforcement 53 on the outside of the end of the frame as shown in Fig.20. This is also done while the frame 1 is pressed outward at the end toreceive 46 as described. 53 is formed of the structure of Fig. 8although any desirable tensile reinforcement may be likewise employed.53 is so also stretched to become pre-tensioned with 46 after the gluingand the release of the frame end from its temporary outward distortion.As 53, so bonded to the frame, serves in a tensile capacity on the topof the two outturned arches 8 and in turn in a compression capacity onthe top of the inturned arch 2, I preferably, in employing the strip ofFig. 8 for this purpose, see that 17 and 18 thereof, and particularlythe outer layer 17, have good compression values. Preferably a suitablemolded plastic or secondly a suitable vulcanized iibre can be soselected for the purpose, it being understood that 18 is such as toprovide a good gluing surface on its exterior for securely bonding sameto the racket frame. The outer strip 17 can be slotted for stringprotection where necessary and in such manner, as described elsewhere,for avoiding the old-time frame distortion, and should be suflicientlyhard to resist the wear and tear of ground abrasion to which the end ofa racket is subjected.

Referring further to Fig. 2U, in this modified form of the frame of Fig.l the two face and crosswise laminations 54, corresponding to 12 of Fig.l, do not in this instance completely circle the frame as in Fig. l butinstead terminate above the throat thereby lightening this heavierportion of the frame as found in the throat and shoulder area oforthodox frames and giving more whip and flexibility at this point.Meeting 54 at its lower ends 54a (which can be located at higher orlower points on the frame as preferred for ditierent requirements) andcovering the remaining shoulder and throat areas and in this instanceextending down the shaft and handle, are the face plate-like members 55,corresponding to 3570i Fig. 1

1d and adhesively bonded to the opposite faces of the racket Iframe. 55,as shown in Fig. 22, has a lamination 55a of liberglas or glassfilaments in one or more ply, adhesively coated and bonded under heatand pressure, as with hydraulic presses to the backing SSb which as inthe similar structure of 35, Fig. 13, is thin resilient homogeneousplastic or vulcanized fibre or lishpaper such as will provide a securegluing surface for the subsequent bonding of these face plates to theframe 1 of Fig. 20 in its completion. For lightening the frame as Wellas providing visual exposure of the highly ornamental liberglas, anouter lamination as 35o of 3S, is here omitted but can of course beincluded when desired, the same as can a ply similar to that of Fig. l0in lieu of 55. The glass filaments may be present in either woven orunwoven arrangement. These filaments 55C, of the layer 55a, are howeverpreferably orientated, as shown, parallel and at right angles to thelongitudinal axis of the frame (as is also the case in 35 of Fig. 1) soas to present maximum and direct resistance on the one hand to thebending stress of the frame in play, which l iind is further disclosedby lacquer checking on the shoulder faces at substantially right anglesto the longitudinal axis of the frame, as would be expected. On theother hand the crosswise extending iilaments directly resist the impactstressing which tends to revolve the frame inward (twist it inside-out)and particularly across the top of the throat so as to stronglyreinforce the important wedge construction disclosed herein. rlhethickness of 55 can be quite thin or gauged up to heavier ply accordingto frame requirements. While the throat may be of standard solid wedgeconstruction, I here in this lightened frame construction employ mynovel wedge 27 similar to 27 of Fig. l, which, when of wood, lpreferably make of three ply construction as shown with 27, Fig. 12a,particularly on account of being cutaway and stressed vertically andhorizontally. In this case I also for still further lightness andincreased whip action cut apertures in the two face plates 55 to conformto the throat aperture 34 as shown. At the same time an unusually strongand safely integrated throat structure is provided by reason of thestrong face plates S5 which substantially cross bond and bind and hold'all the several core members of the throat section together Whilepresenting a lightened and highly resilient structure not heretoforeoffered in rackets. The inherent strength of the shoulder-throat curvebrought about by my acorn. head shape in resisting inward collapse ascompared with the weaker orthodox oval head makes it possible to omitthe extension of my face laminations SLi at the base of the head whereoval frames have in contrast to be heavily reinforced. This simpliiiesthe sanding and finishing work at the throat and avoids cutting into thehighly ornamental surface of the pressed liberglas 55a which is prone tohappen where superimposed wood overlays have to be so finished aspresent in the orthodox wood oval frames. Referring further to the facelaminations 54 and the matter of their application to the frame core,these as shown in Fig. 2-0 use the structure of Fig. 9 with the toplayer 19, however, omitted to lighten the frame. 19 may be included forprotection andfurther strength when so desired, or the structure of Fig.7 or Fig. l0 similarly employed for 54. Also when desired for permittinggreater flexibility or less weight in the arch `2, S4 may be terminatedon both sides of the arch 2 instead of crossing same in one piece. Whileoptional, these two face laminations 54 are preferably adhesively bondedto the frame core after the arch reinforcement 46 (and similarly 53 whenused) has been bonded in place. For greater stiffness in arch 2, in thisconnection, this gluing on of the two faces (54) is also done while ytheframe l' is temporarily distorted outward to lines 52', as alreadydescribed. In such case these face members are preastretched when arch 2is then brought back to its original normal position or still furthertensioned inwardinthe Stringing process. On the other hand, when lessstiffness is desired in arch 2, the laminations 54 can be bonded on theframe core after same has been returned to normal position from itstemporary outward distortion. They can also be made to overlap or coverthe edges of 46 and 53, or not, as preferred. The core of the frame 1can be made as 1a in Fig. 1 or can be greatly varied while still beingfinally completed with the various features of Fig. 20. Where my framesare built for badminton and do not meet the heavy impacts of tennis,they are lightly built to weights around 5 ounces instead ofapproximately 12 to.151/2 ounces as in tennis and to particularlyemphasize whip which is of prime consideration in badminton rackets. Forthis purpose the plate covering of the throat and shoulder area insteadof being that of Fig. 22 and employing the heavier glass filaments canbe made as in Fig. 23 where a core of resilient elastic rubber sheet 55eis adhesively bonded between two thin vulcanized fishpaper facings 55dand 55)c in pre-fabrication in a press, these facings so providing thenecessary protection and the gluing surface for bonding to the framecore members, the frame also being made with more whip, when Wanted,with the thinning 39 of Figs. 1-2.

In Fig. 24 is shown an alternate arrangement of cornbining the crossface laminations as 12, and here designated 56, of reinforcing the frameand providing the protection necessary for the strings, and in adifferent manner. The frame core 5'7 can be of any construction but inthis typical frame section is shown as a five ply of edgewise bondedwood laminations, which also because of being encased with highlyreinforced outside laminations may be of very light wood of less thanthe strength normally applied to frame construction. Red cedar, willow,yellow poplar, spruce, etc., are amoung such woods available. Such acore is glued up with outer laminations 58 and 59 which are located andbuilt to carry a large portion of the stress load, and for that purposehave a core lamination of high tensile-strength glass filaments being ofthe construction of Fig. 8 or my modified equivalents. The `facelamination 59a of 59 is preferably of suitable plastic of strongcompression strength and protects the strings piercing the frame fromwithin the head from direct bearing seat on the somewhat abrasivefiberglas of the core 12 while the inner lamination 591; is thinner than59a and preferably of thin vulcanized fiber to provide a good andreliable gluing surface for bonding the pre-formed 59 to the wood core57, or the plastic can also be used and in greater thickness if itsvaluable contributions are so desired. The pre-formed plied strip 58 isof similar construction to 59. The outer lamination 58a, of plastic orvulcanized bre, can here be thinner than 58b, if preferred, as thestrings may not receive as much abrasive action on this outward seat,and the inner lamination 58b may be vulcanized fibre or the plastic, thesame as 59h. In contrast, however, 58 still further includes anotherouter face member 58e, primarily included for string protection againstground stroke abrasion and without slotting into 58a or the core ofglass filaments 12 to so weaken same or bring the strings to a directabrasive bearing on the glass surface of 12. 58r.` may be of anysuitable material and vulcanized bre may also be used for this. Theslots 7b, as indicated in Fig. 24, for the Stringing 7 are preferablystamped in the libre strip before bonding same to the balance of 58 withadhesive in pre-fabricating the latter. In this way, the usual cuttingof the slots and holes as normally done in a wood racket, can be greatlysirnplified. The readily stamped 58e so provides a templet on the gluedup frame for subsequently` boring the so located holes 7a through thecore of the frame. As it has been found preferable ,in racket making tobore these holes and cut the string slots by hand rather than withcomplicated and expensive machines, it will be appreciated how thepre-stamped strip 58e when embodied in the frame .greatlyfacilitatesthis operation in addition to serving to provide the stringprotection required. 58e is also offset in being glued to 58 as a resultof being cut to a narrower width so as to form corner rabbets 58d forreceiving the face cross laminations 56. Similarly 59 has its edgesbeveled or rabbeted on the corners 59C to receive same. Thus after theedgewise frame core, including 58 and 59 has been glued up andedge-finished for receiving the crosswise face laminations 56, which arepreferably of the form of 12, Figs. 7, 1 and l2, these are bonded tosame as already described for Fig. 1 and, at the corners 58d and 59e,molded about the -frame core, as noted, so as to make an attractivestream-lined frame and at the same time bind the edgewise core memberstogether and against delamination so prevalent in laminated wood frames.At the same time the strings remain protected and without bringing aboutunbalanced distortion as in orthodox wood frames. This is accomplishedby the manner of stamping out 58e as diagrammatically indicated in Fig.25, with regard to the outer extremity of the racket frame where thetrouble noted normally exists. In my stamping, the central holes 60 onopposite sides of the frames central axis A-A are followed symmetricallyon both sides by the slottings 61, followed in turn by the long channelslots 62 on one side and 63 on the opposite side. These points 62 and 63are the ones Where standard Stringing, as heretofore,rrequires quitedissimilar slotting in a wood frame in relation to each other. One sideis weakened more than the other, thereby, with subsequent distortion ofthe frame under string pressure made imminent, as previously discussed.By stamping the two long channel slots 62 and 63 down the center of 58e,this normally unbalanced weakening and cross cutting irregularly of thewoods longitudinalv fibers in orthodox frames is so done away with whilethe irregular formation ofthe standard stringing can still be carriedout within the channeled recesses 62`and 63. One of these channels mustbe slightly longer than the other but this is of no great importance.After the channels 62 and 63, follow again the regular slottings as 64on both sides of the head until the middle portion of the racket isreached and slotting can be dispensed with. It should also be noted thatthe diagonally placed slottings, as 61 and 64, can instead be placed instraight alignment with my construction of 58 which cross-ties the woodframe from splitting longitudinally. In a wood frame with the wood grainall extending longitudinally, this cannot Vbe safely ventured, eventhough the diagonal slotting severs the valuable outer wood fibersacross the frame. My diagonally woven glass filaments of 12, inthemselves, obviate such necessity, providing, as they so do,non-splitting cores in the two outer composite lamina. tions 58 and 59.

Fig. 26 is a modified form of reinforcement for the outer arch 2,similar to 46 of Fig. 2l but of simpler form. This is made individuallyor cut from sheets made up with the three layers 66, 67 and 68. 66 ispreferably a strong resilient layer of plastic bonded on 67 which iscomposed of the adhesively coated liberglas, as heretofore, andincluding longitudinal filaments extending lengthwise of 65. Bondedtherewith on its lower surface is a thin lamination of fish-paper orvulcanized libre, providing a good outer gluing surface for bonding withthe cantilever lamination 26 as indicated, and preferably omitted on thesofiit of arch 2, between the opposed extremities 26 of the laminationor laminations 26. The opposed ends 69 of 65 are tapered away, ,theupper lamination 66 of plastic or other suit,

`able material being either so molded in forming or subsequentlymachined to such shape. The whole integrated unit 65 is designed toprovide a strong spring reacting reinforcement for the arch 2, or ratherthe arch group 8-2-8 for which purpose it is adhesively bonded to theframe as 1 (or 1a) as in the .case of 46 ofFig. 21. VV Similarly to 50of the latter, it is formedwith its end sj69 sopextended upward thatthey haveto be :come

pressed and snapped into place tothe nal shape of Fig. 26`in beingadhesively bonded into the frame as in Fig. 20X;v The samevapplies tothe arch 2, etc., which is first formed to the lines of 52 of Fig. 2O(the temporarily sprung position of frame 1') then later properlystressed in being brought to permanent position as in Fig. 26 after themanner already described. The further spring action is provided in Fig.26 with the inner rim lamination 26 (as in Figs. 1, 14) which can beadhesively bonded to'65 by virtue of the gluing surface provided forthat purpose by the lamination 68. In such case 26 is likewise sprunginto position and tensioned 'as already described, being glued into theframe after 65 is positioned, and preferably simultaneously with thegluingof 65 to the frame. The element 46 of Fig. 21 can be similarlycombined with 26 in the frame when so wanted.

In Figs. 27-28 is shown another alternate spring device for actuatingthe arch structure 8-2-8 with great resiliency and reinforcing same. Theskeletonized elcment 70 is formed for this purpose to the upward dottedshape 70' and with the arch 2 conforming to the outward temporarilysprung line of the frame 1', shown dotted 52. As in the previous similarelements the ends or tails 71 are sprung inward in adhesively bonding 70to the frame 1' (shown in dotted position) and the `end spikes 71a pressinto and mechanically bond to the frame in addition to the adhesivebonding to same ofl the element 70. After the adhesive has nally set,the arch 2 is drawn inward, as indicated, in conjunction With Weavingthe stringing 7 into the Stringing holes in the frame under hightension. In this connection it will beseen that 70 is skeletonized withthe apertures, as 72, so keeping its cutting edges `away from thestringing passing through same, as shown in dotted line, and the weightof 70 also so reduced to a minimum while still maintaining a strongresilient structure in which the outer bands 74 and 75 are struttedapart by the cross ties 73. With thin `gauge steel alloy, such as chromesteel, properly heat treated and tempered, a strong resilient spring maybe had with little additional weight added to the frame. Other materialmay also be used, however, for 70, including a plastic or resinv laminaformed with glass filaments extending longitudinally as part of afabric, or otherwise, it being remembered that the glass filaments willnot take a set which is of prime importance in the permanent andresilient working of the arches 8-2-8. If 70 is of metal, specialbonding adhesives or cements are available for securely bonding same tothe frame. lf 70v is a berglas lamina or' other formed material whichmay present a questionable gluing surface, then a thin bre inner facingmay be bonded on 70 in its original press pre-fabrication which willgive the desirable gluing surface for joining to the frame as in theprevious descriptions.

In Figs. 29 and 30 are shown some additional or alternate features forthe frame extremity of Fig. 14. In Fig. 29, the frame 1a is provided notonly with the compression and thickening reinforcements 40 in the lowerportion of the arches 8, as in Fig. 14, but in addition includes asimilar compression insert 40' in the top of the arch 2, as indicated.Thus 40 and 40' strengthen the three important reacting arches 8 2--8and also dispose the tensile laminations 12 in position to provide amore elective pull as regards each of these arches. The effectiveness ofthis tension resistance is further secured and enhanced by the envelopesor binding 76 and 77 securely bonding these laminated arches together atthe three strategic points and reinforcing same both againstdelamination and failure. 76 and 77, the same as 44 of Fig. 14 arecasings preferably of glass laments in a resin or plastic matrix castunder suitable heat and pressure on the frame at these points, theglass, of course being immune to moisture absorption which is highlyimportant in the functioning of these casings.

. 20l NylonA is another good ber for the purpose but not as strong. Theauxiliary spring, reinforcing elements of Figs. 21, 26 and 27 may alsobe added to the frames of Figs. 29 and 30. Fig. 30 does not include theinserts 40 and 40' inthe arches 8-2--8, and in addition to the berglaslaminations 12 in the frame structure, as in Fig. 14, includesadditional similar tensile reinforcement added to 12 inboth the top andbottom portions of the arches 8-2--8,v as indicated, 78 and 79, toenhance their functioning. In addition thereto, when wanted, acontinuous tensile wrapping 80, as shown in dotted line, similar to 44and preferably employing glass filaments, is cast about and encases theframe along the arches Figs. 31-42 indicate, somewhat diagramatically,modied forms of my racket frame structure and their making, employing myglass and other tensile lament structures similar to Figs. 7 and 1,etc., to meet the torsion stresses disclosed by Figs. 3 and 4 andprovide further highly novel frames of unique structure and qualitiesmade possible by these lament structures both with and without woodlaminations. Great strength and resilience,` dimensional stability andlightness of weight and low air resistance with small framecross-sections are so made possible with the unrivaled properties of theglass lilaments in particular and the high fatigue resistance offered bysame. The laments or bers forming the structures are coated withtheproper adhesives in all cases, and porous bers, as distinct fromglass, may be also impregnated to more or less degree.

Re. Figs. 31 and 32, in Fig. 32 is shown a cross section of the racketframe in which my laments are arranged in strategic formation to meetthe torsional and likewise the bending stresses, the frame beingpressure molded with its body formed from the simple flexible andpliable assemblage shown diagrammatically in Fig. 31. For such purpose,my berglas braided tube structure, herein numbered 81, in any desirednumber of tube ply or thicknesses (in this case two, 81a and SIb) onedrawn within the other, has a ber core lling. This core can be variouslycomposed but preferably when a solid frame is wanted is formed with acore 82 of strong but lighter Weight and cheaper ber, as for examplesisal, bow hemp, manila hemp or other desirable fibrous material, eitherin straight loose or braided form, or as a twisted rope. About the core82 is arranged an outer layer 83 of stronger and longitudinally disposedlaments, preferably glass, and the core assemblage so arranged is drawninto the tubular member 81 while in a straight length. To the outeropposed sides of the tube 81 are attached, as by sewing or tacking 86,two twisted cords 84 and 85. These are of light-weight inexpensive bte,as jute, sisal or the like for forming unabrasive seats and bearings asprotection against the abrasive glass fibers for the Stringing when theframe is subsequently molded in hardened form. Because of the diagonalarrangement of the tube filaments of 81 and the loose or twistedorientation of the other bers or filaments longitudinally, the tubularelement 81 with its llings and cord attachments is highly pliable andadaptable to curved forming with simple finger-placing in the racketform prior to its molding therein and the hardening or polymerization ofthe adhesive, coating and embedding the various fibers. Thus, in itsuncured stage, it is laid in the racket molding form about a centralhead form (not shown in Fig. 32) on the base platen 87 and thereafterpressedagainst same by the outer circumventing expandible uid pressuretube 90 made of rubber or other suitable material operating between anouter form wall 89 and an inner face shaping member 91 which can bepre-shaped out of thin sheet metal, molded plastic, rubberor'equivalents. Suitable uid pressure (with heat when wanted) is appliedin 90, in its initially collapsed position, after 81 and any additionalframe parts to be glued to same, such as throat or handle wedges, etc.,are properly assembled in the form and the latter closed with the topcovering plate or platen 88 which extends over the assemblagethroughout. It will be understood that 81 iS extended to form the head,handle shaft and handle base, corresponding to the frame laminations asin Fig. l. In the pressure molding 8l is compressed and reshaped afterthe manner indicated in Fig. 32 and the cords 84 and 85 pressed into thebody of 81 as indicated to provide the string bearings, the holes 7a,for which, are drilled into the formed frame after its removal from themold, after the adhesive hardening process has been properly completed.The member 34 is so disposed in the groove molded into the frame for theproper protection of the Stringing on the outer edge of the frame asindicated. As a result of the above a Strong resilient light-weightframe can be formed with a notably Strategic location and orientation ofthe strong glass fibers and with a strong but light-weight core. Theframe iS preferably made to the form of Fig. 1 or 20 but can likewise bemade to the conventional oval type or other shapes as wanted. Aside fromparticularly providing against the torsional Stresses as indicated inFigs. 3 and 4, the frame does away with the necessity and difficulty ofbending stiff wood laminations met with in common racket construction,as well as the notable deciencies inherent in wood While the unrivaledproperties of glass fibers are capitalized to great advantage and bytheir particular positioning with regard to the frame cross section.

Figs. 33 and 34 show a similar but modified construction and a hollowtubular frame form in place of the solid core of that of Fig. 32. A tube93 of pliable rubber or the like or a suitable thin film wall, has arope or Similar core 92 inserted in same to form a mandrel on which,while in the straight, is drawn a tubular member 96 consisting of one ormore braided tubes, preferably formed with glass filaments or fiberglasAbout this is placed a covering wall 95 of longitudinally disposedtensile filaments, again preferably glass although for lighter weight orless expensive frames other Strong fibers, such as already suggested,may be used. This so mandrelmounted assemblage is disposed within anouter covering 94 consisting of one or more braided tubes preferably ofglass filaments, either by drawing same into the tubes or braiding Sameabout such a core. The fibers of 94, 95 and 96, which are to serve instructural capacity are coated with the adhesive at Such point in theoperation as is preferred, likewise the string bearing strips 9S and 99corresponding, respectively, to 84 and 8S of Figs. 31-32. As in theprevious case, this bearing can be either flexibly attached to the tubeassemblage or properly located in the mold form so as to adhesively bondto the frame tube in the pressure molding of the frame. A strip ofsuitable pliable material may be used for this bearing in lieu of thefiber cord in all cases, or it may be only flexible rather than highlymoldable throughout, as for example a strip of vulcanized fibre. Anadditional edge member 97 (as distinct from Figs. '3l-32) is alsoincluded although this may be omitted when desired. This is preformedand provides an outer shell facing for the outer edge of the racket, atleast for the head portion or a desired length thereof. This is made outof high strength, resilient plastic or other suitable material,preferably preformed to the contour of the frame and placed in the formsimilarly to 91 of Fig. 32. In contrast, however, 97 becomes adhesivelyintegrated to 96 to form a permanent part of the racket frame and towardthat end, when necessary, has its inner and bonding surface coated withadhesive prior to being placed in the form whereas 91 is an operativemember of the form only and has its face which contacts the framematerial protected with anti-adhesive material or other customaryprotection for Such end. 97 can also be formed of high tensile strengthsteel allo'yl or other metal or of adhesive coated glass or other strongfibers as a pre-molded unit. After the molding of the frame iscompleted, the tube 96 has been given, along with its contents, etc.,its final shape with a cross section after the manner of Fig. 34. Therope mandrel core 92 is pulled out of the inner tube 93 to provide thehollow chamber 100. To facilitate such removal it is possible, ifnecessary, to have same in two pieces meeting at the outer center of thehead frame and furthermore to coat 92 with a suitable lubricant. be donewhile 96 is still in straight position. Thereafter, 93 is inflated andsubjected to internal fluid pressure (heated when desired). This fluidpressure can be relied upon by itself for the final forming of the tube96 and its accompanying assemblage in a suitable confining form Withoutthe aid of an exterior fluid pressure tube as of Fig. 3'2, or the twocan operate concurrently, both from within and without. In this way avery strong but light frame cross section with its hollow center 100 maybe had. The outer edge-facing shell 97 protects the matrix embeddedglass fibers of 94 against ground wear and injury aside from providingadditional strength, resilience and decorative enhancement. A suitablenonabrasive and Slightly cushioning strip 98, such as chrome, leather orother desirable material is preferably glued in the protective channelformed by the shape of 97 which protects the Stringing where passingbetween the stringing holes 7a. u

In Figs. 35-36 is Shown another modified arrangement of my fiber filledbraided tubes and the frame section so produced. Therein, 101 and 103are braided tubes of one or more ply, as desired, and preferably againof glass filaments. These tubes are placed on the outer sides of anotherand central braided tube 102, likewise of oneor more ply or wallthicknesses. The tube 102, however, is braided with strong butnon-abrasive fibers, as distinct from glass, such as sisal or the like.The tubes 101 and 103 have a filling consisting of top and bottom glassfilament cords 104 and 104 respectively, which are separated bylongitudinal tensile filaments 105. In lighter weight frames or of lessstrength these may be of sisal or other strong vegetable or syntheticfilaments of desired lightness but in the strongest and heavier framesglass filaments are preferred for 105, or a mixture of glass and thelighter fibers may be employed. In contrast, however, the non-abrasivecentral tube 102 is filled with longitudinally disposed non-abrasivefibers 01' material rather than glass fibers. Such suitable fibrousmaterial may include the strong manufactured filaments known as nylonand another Fortisan, or the cheaper vegetable fibers or mixtures ofseveral Such. Positioned as shown in Fig. 35, the tubes as filled areassembled together as .indicated and secured together as with diagonalstitching 107 (which readily adapts itself to the subsequent curving ofthe tubes) and in this form can be freely flexed and inserted in theracket receiving form as in the similar previously described cases. Toprovide greater resilience in the finally molded and hardened framepressed in the form and particularly its resilient arches the hightensile-strength fiberglas cords 104' are preferably pre-stretched ortensioned in the form prior to the molding operation (which can be doneafter the manner subsequently described with Fig. 43). This isparticularly important with regard to the inturned arch 2 (as in Figs. land 20) where T04 lie in the important and tensile sofht of Same. Itshould also be noted that these four high tensile-strength cords 104 and104 are carefully located in my structure at the four corners of theframe Section so as to provide the maximum of strength and in alldirections in accordance with well known engineering laws and resistwith great advantage the bending Stresses to which the frame issubjected by the blows at right angles to the plane of the Stringing aswell as the stress of the high tensioned Stringing against the frame inthe plane of the Stringing. It should also be observed that the holes 7afor the racket Stringing are drilled throughout in the central tubularlamination 102 and therefore entirely in non-abrasive material, socombining Its removal may preferably most eeetively the high strengthglass iilaments in the frame without abrasive danger and in most simplemanner.

Fig. 37 shows another simple modified form of the frame section in thisinstance produced by employing my tube element 108 of any desired numberof ply or walls of the tubular braided glass laments with my interiorfilling and with exterior string seats molded into same. The filling of108 herein consists of the spaced apart high tensile strength cords 109and 109 of glass iilaments strutted apart by a web member, in this caseformed by pre-gluing together as in a press a central light-weightcellular core 110 of expanded plastic, such as cellular celluloseacetate known as Strux, or equivalent, with facings 111 of hightensile-strength glass iiber tape, with unidirectional longitudinalfilaments preferably in preponderance, and outer facings 112 of thinvulcanized fibre or iishpaper glued to same to provide outer surfaces ofgood glue bonding character for later bonding with 108, which thepreformed glass ber matrix body does not provide in itself or with thesame surety. This pre-glued and pressed composite strip with itslight-weight core and high-strength outer facing is placed between thecords 109 and 109' so as to strut same apart and the group so drawn intothe braided tubular element 108. The nonabrasive string bearing strips113 and 114 are then attached to or combined with 108 after the mannerof Fig. 3l or properly located in the racket mold for such purpose andthe adhesive coated elements as heretofore explained are shaped andbonded together in the mold form to provide the racket frame and atypical cross section as shown. The string bearings 113 and 114, insteadof being formed of fibrous cords, may be of pre-formed strong plastic orwood, either being preferably here ernployed as pre-shaped strips. Thelight strong cross section of Fig. 37 is particularly suitable forlight-weight badminton rackets but can also be used for the tennis andother racket frames. It should be noted that the Strux cores 110 bythemselves could not be bent to the form of the racket without snappingat various points of curvature but by applicants combining these withtheir facings of glass and/or fibre while glued up in the straight, itis then possible to bend same as wanted without this diiculty.

In Fig. 38 is shown another alternate form of frame section employingtwo of my tubular elements similar to that of Fig. 37 and in furthernovel combination. The outer braided glass lilament tubular element 116is filled with the opposed .tensile fiberglas cords 117 strutted apartby the band or wall 118 of longitudinal glass fila- .i

ments while the similar tubular element for the inner edge of the headframing is iilled with the glass filament cords 117' and wall 118, 117being preferably prestretched after the manner of 104' of Fig. 35. Astrong I beam shape is given the filled tubes 115 and 116 in the fracket pressure molding by embedding in them of the relativelylight-weight strips 119 and 120, and 121 and 122, respectively. Theinner filler strips 119 and 121 can be of expanded plastic, as Strux, orlight balsa wood or stronger heavier wood or other suitable material asdesired. The outer and string support strips 120 and 122 can be the sameas 113 and 114 of Fig. 37 and made to add structural support andresilience to the frame when so desired. Between the two opposed andfilled tubular 'elements 115 and 116, there are one or more laminations,in this case two, 123 and 124, adhesively bonded thereto in the moldingof the frame. These can be good structural Wood or other material. Theentire assemblage is adhesively united in the press similarly to theothers.

Fig. 39 `presents another alternate racket frame section where a stronglight-weight and a tubular frame is secured with my braided tubestructure after the manner of Figs. 33-34. The braided glass filamenttube 125 in any desired number of plyhere shown in two suh,

'12511 and 125bis formedfwith a hollow core 126 by A the means of atemporary pliable mandrel core 92 in Fig. 33 and a rubber or othertemporary tube as 93 of Fig. 33, both of which in this case have beenwithdrawn-the permanent tube structure 125a-125b being molded withexpanding uid pressure applied within the temporarily employed core tubesimilar to l93 after the mandrel core, as 92, has been withdrawn, andadhesively bonded to and between the outer preformed edge laminations127 and 128. These can be formed of strong resilient plastic or plasticlaminas with fibers of high tensile strength Such as nylon, Fortisan orvegetable fibers, or structural wood of desired weight and strength maybe used. The strips are preferably hollow backed 129, as shown, orscoriated or provided with other mechanically interlocking or bondingmeans for engagement with the walls 125 which are adhesively bondedtherewith in the molding and hardening of the yadhesive covered fibersor filaments, the strips being first positioned in the slot of themolding forrn with 125 placed between them. ln lieu of a rope or similarmandrel core as 92, and in the case of either Figs. 33 or 39 or thelike, other removable core material Such as low melting metalpreparations used for such purposes, or contained oil or other fluidsmay be so employed and later removed. After the frame is molded andremoved from the form, the Stringing holes 7a are drilled, passingthrough 127 and 128, 127 being provided at the proper points with agroove or slots for string protection from ground abrasion. When desiredthis frame can also be made solid by providing a permanent core in 125after the manner of 82, Figs. 31-32.

In Fig. 40 another such core filled frame section is shown. The outertubular braided wall or walls 130 are filled after the manner of 81 ofFig. 31 and the outer string bearing strips and 136 (similar to 84 and85) attached thereto or properly positioned in the rmolding form. Thefilling of 130 consists of a core 134 of longitudinally disposed fibersin twisted or braided rope form or merely bunched and combined withuncured adhesive prior to the pressure molding of the frame. On theopposite sides of this core material are placed the additional braidedand filled tube elements 132. Each of these two tubes has a glass bercord 131 at the top and another 131' at the bottom strutted apart bylongitudinally disposed filaments 133 of Vglass or alternately lighterbers or a mixture of both. The inside high tensile-strength cords 131can be stretched or pre-tensioned as elsewhere described when desired.When this assemblage with its adhesive coated fibers is molded, asheretofore, an exceptionally strong frame cross section as shown in Fig.40 results with the strong corners, similar to Fig. 36.

Fig. 4l shows another modied form of great strength in relation toweight, the racket frame so formed having two hollow tubular cores 144extending throughout its length along with the four strongly reinforcedcorners. The outer shell is formed by the braided glass filament tubularelement 137 in one or more thicknesses and within this are inserted thefilling members as in the previous similar cases. In the two outercorners are the glass fiber cords 140 and correspondingly on the twoinner corners are the similar cords 140' extending longitudinallythroughout the length of the racket frame, as do the two opposed innertubular members which are also Ipreferably of braided glass lamentsalthough other klighter fibers can be used for same. Between these twoopposed tubes (both of which can have a plurality of wall layers whendesired), the tube 137 is partitioned by longitudinally extendinglaminations of any desired number, in this case three, 141, 142 and 143,while on the outside are the Stringing bearing non-abrasive cords orstrips 138 and 139 as heretofore described, through which the Stringingholes 7a are drilled after the frame is press molded and the variousfibers or filaments and laminations adhesively bonded throughout to formthe Z integrated racket frame as previously detailed. The centralpartition laminations can be of any suitable material or materials butin this instance, in order to provide both lightness and strength, 141and 143 are of glass filaments in form giving at least a preponderanceof longitudinal strength while the core lamination 142 is of expandedplastic, as Strux, and to facilitate the bending of same to the rackethead contours in the loose assemblage, this has thin fibre or fishpaperfacings 142 pre-glued to its opposed faces as indicated. When wanted,diagonal stitch tacking (as 107 of Fig. 35) is passed through 137 andthese partition laminations, also including 138 and 139 as preferred,holding 137 in two tubular divisions. It will be understood that whenthe inner tubular members 145 are inserted in 137 along with the othermember elements, the core chambers 144 are occupied by the core mandreland covering tube (for interior liuid pressure in the press forming ofthe frame), the same as 92 and 93 in Fig. 33, or their equivalentsalready described. The finished frame section of Fig. 41 is shown withthese withdrawn, this being done at the desired time in the assemblage,preferably while the filled 137 is in the straight. However, the formingtubes `as 93 can be left permanently in the frame, particularly ifformed of thin film, the frame being formed after the manner of Fig. 170of my co-pending application Serial No. 492,914, above referred to.

Fig. 42 Shows another alternate racket frame section with the containingtubular element 146 of braided glass filaments and in walls of one ormore thicknesses provided with a filling including a plurality oftransverse laminations. The outer corners are occupied by longitudinallydisposed tensile fibers 149, preferably glass, inserted in the fillingof the tube as twisted cords or as merely 'hunched filaments which areconformed in the pressure molding later to the molded form as noted. Theinner corners are occupied by similar filaments 149. interposed between149 and 149 are, in order, 150 composed of one or more thicknesses, twoshown here, of tape of strong tensile fibers, preferably glass, withemphaSis on longitudinal strength. Woven tape of the unidirectional typecan be so used to advantage but regularly Woven tape can be employed.This bears on a lamination 151 of wood, the grain of which preferablyextends longitudinally of the tube and frame. Next is a lamination 152of light-weight or low specific gravity (expanded plastic Strux being asuitable material for same), with its two bearing faces having thinvulcanized fibre or fishpaper 157 pre-glued to Same as heretoforedescribed. This is similarly followed -by the laminations 153 of wood,154 of Strux, 155 of ywood and 156 of the tensile tape the same las 150.153 and 155 have their grain preferably longitudinally disposed thoughin some instances it may be desired to run the grain of the centrallamination 153 crosswise of the frame section instead. 154 has the fibrefacings 157, the same as 152. In assemblage, the various laminationshave their faces coated with the adhesive as required for completeintegration in the subsequent press molding, the various filaments orfibers being of course likewise coated as in all previous instances.

This tube filling of laminations and filaments is assembledV in thestraight and drawn into the tubular element 146. If necessary tofacilitate this end and avoid edges catching in the braided outer tubecasing, a tubular wrapping or covering of cellophane or the like can beapplied about the filling before drawing same into 146. If cellophane isso employed, this can `be withdrawn after the filling has been placed in146, but if instead Ia film or sheet with a good adhesive bondingsurface is employed, this can be left in with the filling if preferred.The filled tube 146 also has the Stringing support cords or strips 147and 14S combined with it, as heretofore. The mold form in which 146 isplaced and molded into the racket frame, as heretofore, is shaped togive Ia cross section in the head such as indicated in Fig. 42 and withthe pressing in of the outer string support 147 and theprotective-groove in which it lies preferably forcing a slight curvatureinto the filling laminations as indicated. This gives a strongerresistance to collapse of the frame with the strong string pressure inthe head and a more resilient support of the Stringing woven through thestringing holes 7a which are drilled through the molded and adhesivelyintegratedA frame after its removal from the molding press. As in othersof the previous varied frame sections, 146 can also have an outerprotective and resilient cover shell, as 97 of Fig. 34, also providedand included in this molding and adhesive integrating of the racketframe.

Fig. 43 indicates the manner of adhesively bonding together the edgewiselaminations of the fratrie of Fig. 1 iand the like, in a press. Thepress, as indicated and corresponding to 87-91 of Fig. 32 (with otherportions not shown in the latter), includes a base platen 159 withformed recess 159' for receiving the frame assemblage' and fluidpressure tube 161, all of which are enclosed lby the upper cover platen158 corresponding to 88 of Fig. 32, which can hinge 158 on 159 and beheld tightly on same by its own weight or by any clamping or lockingmeans when necessary. The edgewise laminations of the frame 1a are soheld in the recess of the form and in the head portion lbetween a centerhead form 160 and an outer thin forming strip 162 of thin metal, plasticor otherv siutable material which is properly pre-shaped or molded tothe desired form and functions, as does 91 in Fig. v32, onv the face ofthe pressure tube 161, corresponding to 90 of Fig. 32. The throat wedge27 and handle wedge 38, with their intended gluing surfaces properlycoated with the bonding adhesive, are also properly positioned in thepress lform along with the longitudinal frame laminations for theedgewise core, yall of which are of course properly coated with thenecessary adhesive for bonding and integrating the frame throughout.After the assemblage is completed and the press closed with 158,suitable fluid pressure is introduced` at the intake 161a of 161 ascontrolled by the valve 161b, the pressure fluid so entering Va T formand proceeding simultaneously from the outer extremity along both sidesof the head framing and out through the tube outlets at the handle end161C. In this way the on-coming iiuid pressure entering 161a tends toforce the loose and curving laminations of the frame 1a forward from theouter extremity to the handle end, so avoiding trapped bulges of thelaminations which would tend to occur, however slight the degree, if thefluid pressure instead entered from the handle end or ends. Thelaminations resting in the recess form 159 are free, as they are beingcompacted, to be pressed forward at the handle end by the fluidpressure, the recess 159 being provided with continued open space atthat-end for permitting or facilitating such forward movement of thelaminations. A further feature is provided at the handle end of thepress for pre-stretching or tensioning the glass or other tensilefilaments 14 of the edgewise laminations 12. These sets offilaments areextended outward at the handle end and the pairs of same from each sideof the frame or handle shank are clamped, tied or otherwise suitablyheld together at their ends 14', as indicated, so as to anchor aroundupright anchor pins 166 at the end of a yoke or clevis 164 which is heldand pivots on an anchor pin 165 which connects with a tensionregistering gauge 163 which is drawn away from the press platen by theoperative screw 167. By this latter means the filaments 14 can bestretched while in their assemblage in the press to the properpre-determined tension as registered by the gauge 163. This is done inconnection with the application of the iiuid pressure, either before, atthe same time as, or after the pressure is in the tube, as may be foundbest, but in any case the filaments are thus tightened before theadhesive surrounding them and coating the various elements of theassemblage is cured and hardened. After the polymerization or hardeninghas aifspao been properly completed, the fluidgpressure isremoved andlthe racket, so glued throughout, is removed from the press form whichhas of course been provided with the customary protection againstadhering to the racket frame, such as coatings of cellophane or otherprotective lm for keeping the form free. The next step is that ofapplying, molding and adhesively lbonding the lface cross laminations 12to the edgewise formed frame core which is subsequently accomplishedafter the manner indicated inFig. 44. A very desirable manner ofemploying the fluid pressure, above, is to have the platen pressenclosed in a vacuum case or have the opposed platens join airtight soas to provide a vacuum box in themselves from which the pressure tubeintake and outlets extend and means provided for evacuating the air inthe press so arranged. In this way, after 4assemblage is complete andthe press closed, the interior air is removed from the assemblage andpress interior while the atmospheric pressure is allowed to enter at16111, in accordance with well known procedure. When so depending onatmospheric pressure, suitable contact or low pressure adhesives are ofcourse employed but higher than atmospheric pressures can still be usedin 161 while still vacuuming the press which insures a still betterbonding and compressing together of the assemblage elements and removalof air pockets. Where heat is required for a particular adhesive, thiscan be supplied in the regular way land with heated duid in 1 61 and! orheated platens or by high-frequency dielectric heating, etc.

In Fig. 44 is indicated the manner in which the cross face laminations12 are molded to the edgewise laminated head frame core as of Fig. l,the cross section of `the racket frame being taken at a point beyond thetermination of the reinforcement 15 and so composed of the remaininglaminations 21, 12, 22-25, 12-12' and 26 as disposed in Fig. 12. Thepress in which this gluing and molding is done follows the generallayout of the head portion of Fig. 43 and includes a bottom platen 168,an inner head form 169, an vouter form 171, a fluid pressure tube 172,operating against the latter on the outer side and against a shapingstrip 173 with a projecting groove forming strip 173' on the inner orframe side, 171 to 173 inclusive, of course extending around the outerperimeter of the entire frame or at least the head portion and 173extending as far as the string protecting groove, formed thereby in themolding of the face laminations 12, if desired. At the bottom of themolding slot formed by the press elements in which the previously gluedup edgewise frame core is placed, is another pressure molding tube 174operating between the base platen 168 and a molding strip 174 forproperly shaping the lower face lamination 12 in bonding the latter tothe frame core. Similarly, at the top is another pressure molding tube175 which operates at its bottom against the molding strip 175' forshaping the upper face lamination 12 which is placed in the mold on topof 12 after same has been placed on the frame core which is introducedinto the press on top of the lower face lamination 12 after the latterhas been placed on top of 174. Both the upper and lower laminations 12have their filaments coated with adhesive in the uncured stage, or notthe finally cured stage at this point of the operation. When the pressis so filled it is closed and locked with the top platen 170. Theforming fluid pressure is then applied, first through 172 to tighten upthe sides of the mold against the assemblage and then the fluid isapplied simultaneously in 174 and 175 so as to shape, mold and compressthe faces 12 onto the frame core and adhesively bond same together withthe polymerization or hardening of the adhesive employed. The lowerpressure tube 174 may be dispensed with and the pressure provided forboth top and bottom by 175 but more even pressure on both the opposedfades will be assured hy the use of the two tubes which are sopreferred. It is also possibleY to employ the same press 28 forperforming the operations of both Figs. 43 and 44 by combining thefeatures of the two presses in one when desired and in such case it isalso possible to do both operations of gluing the core members andapplying the face cross laminations to same simultaneously in one gluingoperation, if preferred. When the edgewise core is first glued togetherin a separate operation,'it ordinarily would have its two faces sandedbefore gluing on the two face laminations but when using a pliable andreadily molded filament body such as 12 which can so accommodate itselfto irregularities in edges of the frame core laminations, it is possibleto eliminate all or part of such sanding in many instances, by reasonthereof. Also, because of the bias disposition of the filaments of thecasings (13 of Fig. 7), the latter are readily layed around and adaptedto the curving head shape of the frame core when placed in the pressslot therewith. After the molding and adhesive bonding operation iscompleted in the press, the integrated frame, which has been properlyprotected from adhesion to the press mold, is removed therefrom. Withcareful and skillfully handled molding there should be required littleif any dressing or sanding thereafterin contrast to orthodox framegluing. The Stringing holes are drilled in the frame which is then givenany desired lacquer or other finish if necessary. It should also beunderstood that while in Fig. l the facings 12 extend around thecircumference of the racket head they may also or alternatively extenddown the throat sides and handle shanks 1b so far as and when sodesired-or they may be omitted from portions of the head frame wheredesired and as in thecase of Fig. 20.

1t should be further noted and particularly in connection with thepre-stretching or tensioning of the glass filaments 14 of the edgewiselaminations 12 by means of 167 of Fig. 43, that this is in addition toor auxiliary -to the tensioning also given these filaments when and ifthey are glued into the frame when the frame or frame assemblage istemporarily distorted outward, particularly with regard to the inturnedarch 2, as previously outlined. This will be taken into consideration indetermining the degree of pressure applied with 167. Of course eitherone of the tensioning means may be omitted and reliance placed on onealone. Where a pre-glued type of tensile reinforcement as 15 of Fig. 8is used in place of 12 of Fig. 7 for the edgewise laminations 12, thepre-tensioning as by 167 cannot be employed although, in accordance withrecognized practice, the prefabricated lamina may have glass filamentsbonded while in tension therein, or in the case of 15 of Fig. 8 mytensile filaments 14 may be drawn and stretched within the tube 13 inthe pre-fabrication `of 15 by tensioning means similar to 167 employedin Fig. 43. Also it will be noted that whereas the face laminations 12,because of their horizontal position cannot have their filaments 14tensioned by 167 or similar means Without pulling out of positionparticularly in the vital arches 8-'-2-8, nevertheless do have boththeir filaments 14 and those of the tube 13 stretched or tensioned bybeing glued to the edgewise laminations while the latter are distortedoutward temporarily in the arch 2, etc., while the gluing or adhesivebonding is being perfected. The same applies to 16 of Fig. 9 when sameis used alternatively for the face laminations of Fig. 1 in lieu of 12of Fig. 7.

It should be also noted that in the coating of the filaments of 12 andthe like with the bonding adhesive that only the requisite and not anexcessive amount of adhesive be retained thereon and in the assemblage.Toward this end, I preferably insert the filaments 14 in the tube 13(forming 12) and submerge same in a tank bath of the liquid adhesiveafter its being and While exposed to a vacuum which removes the air andforces vthe adhesive throughout the assemblage which in turn passesthrough a series of alternate vertical and horizontal pairs of rollers,or equivalent, in the bath, so that the uid is distributed thoroughlythrough the mass. The excess adhesive fluid is then removed as 12 passesthrough a nal pair of roller wringers above the bath in leaving thelatter. Glass filaments, having no porosity, do not as readily retainuncured adhesive as do vegetable or porous fibers. Accordingly, whennecessary or desired, I mix throughout or with the bundle of glassfilaments i4 of l2, some strong vegetable or porous bers, as sisal forexample, in proper proportions which can also be varied for lighteningof weight where such is also a consideration. `As the fluid adhesiveimpregnates pores of these porous tigers, this is taken advantage of sothat in the final press forming, as in Figs. 43 and 44, a proper excessamount of adhesive carried in pores of the porous libers can be squeezedout onto adjacent glass lilaments or through the assemblage so assuringbetter coating and `bonding of same in the final structure. Such fibermixtures, proportioned to suit, I also use in the lighter-weight racketsin any or all parts when and as desired. Throughout the frame thematerials employed may be greatly varied in substance and in combinationwithout departing from my invention. Throughout the drawings it will beunderstood that glue lines are represented as the contact line ofadjoining laminations and parts that are integrated in the structure byadhesive and the bers or filaments are indicated as in their adhesivecoated contour. No attempt is made to depict accurately, fully orotherwise, allowance for compression of the materials and in differentdirections which will or may occur in the molding and adhesiveintegrating which will vary with the nature of the materials employed,etc., and must be properly provided for in each respective case in thedesign of molds, dimensioning, etc. The assemblage and forming proceduremay also be greatly varied and modified as well as the shapes.

Thus, while l have shown and described my invention in a preferred form,l am aware that various changes and modications may be made thereinwithout departing from the principles of the invention, the scope ofwhich may be determined by reference to the appended claims.

I claim as my invention:

l. A racket frame having a curvilinear head portion subject to torsionaland shearing stresses and designed to hold tight Stringing underpressure and including a plurality of elongated laminations, includingat least one wood strip, bonded with an adhesive substance to theexterior of a longitudinally extending tubular element includingelongated tensile filaments combined with adhesive and in braidedformation and so as to particularly provide substantial structuralreinforcement against torsional and shearing stresses and extendingalong said head portion at least at a point subject to such stressing.

2. A racket frame having a curvilinear head portion subject to torsionaland flexural stresses and including as a structural part thereof atleast one longitudinally extending braided tubular element, formed withtensile material of high tensile strength, and a plurality ofindividually formed, longitudinally extending structural tensilefilaments separate therefrom but contained therein and bonded with ahardened adhesive substance to said tubular element', said tubularelement and said tensile laments extending along said head portion atleast at a point subject to said stresses.

3. A racket frame having a curvilinear head portion subject to torsionaland shearing stresses and including at least one longitudinallyextending braided tubular structural element disposed to resist suchstresses and support under pressure tight Stringing which is vulnerableto abrasion and including tensile filaments, at least some of which areof an abrasive nature, coated with a hardened adhesive substance and atleast one elongated strip of substantially noni-abrasive materialadhesively bonded to said element and interposed between same and saidStringing.

4. A racket frame including in the outer half of the head opposedlaminations strutted apart by a plurality of edgewise laminationsdisposed at an angle to same, said opposed laminations forming humps onthe frame with at least the greater portion of the peak of the humpdisposed outward from the central transverse axis of the head.

5. A laminated racket frame having a curvilinear head portion subject todistortion and flexural stresses and having opposed longitudinallyextending structural face overlays strutted apart by a core adhesivelybonded therewith and between same, said overlays being channel-shaped incross-section so as to thereby more strongly resist the ilexing of theracket and securely embrace the core within said channels and so alsobetter resist distortion of the head portion and splitting of the core.

6. A resilient racket head frame forming an enclosing head portion forreceiving Stringing therein under strong tension and including at leastone inturned string-supporting arch with at least one strong tensilereinforcing lamination including longitudinally extending glass fibersadhesively bonded in said frame and inturned arch portion and with itsliber structure in such stress relation therewith as results wheneffecting said bonding while at least a portion of said inturned arch istemporarily distorted outward of the head and at least a portion of saidreinforcing lamination, designed to form a strong tensile reinforcementfor said inturned arch, is distorted inward of the head so that whensaid portion of said arch and said portion of said reinforcinglamination, after being so adhesively bonded together in the abovedescribed stress relationship, are bent further inward of the head instringing or in play, said reinforcing lamination is more highlystressed in tension than said portion of said arch.

7. A resilient racket frame having a curvilinear head portion designedto hold tight stringing under pressure and having an inturned arch atits outer extremity particularly subject to distortion, said arch beingreinforced against said stresses by thickening of the frame alongsurfaces of said arch and the head at the same time so strengthened toresist the normal tendency of the head to hinge inward on the racketscentral longitudinal axis with ball impact on the Stringing.

8. A racket frame subject to tiexural, shearing and torsional stressesand including a plurality of spaced-apart, exteriorly positionedlaminations disposed at a zone subject to such stresses connected byinterposed elongated structural filaments of high tensile strength andcoated with a hardened adhesive substance, certain of said ila,

ments being disposed in braided tubular formation and particularlyproviding against shearing and torsional stresses and being incombination with other unbraided filaments particularly providingagainst iiexural stresses, said filaments and laminations being bondedtogether by a hardened adhesive substance.

9. A racket frame subject to flexural, shearing and torsional stressesand including at least one longitudinally extending, exteriorly exposedlamination disposed at a zone subject to said stresses bonded with anadhesive substance to strong tensile structural filaments coated with anadhesive substance and disposed in helical tubular formation designed toresist shearing and torsional stresses, and extending in oppositediagonal directions.

10. A racket frame subject to tiexural, shearing and torsional stressesand including at least one longitudinally extending non-metalliclamination disposed at a zone subject to such stresses bonded with ahardened adhesive substance to elongated glass ilaments coated with ahardened adhesive substance and disposed in helical tubular formationdesigned to resist shearing and torsional stresses.

1l. -'A racket frame having a curvilinear head portion subject" totorsional and shearing stresses and including a lplurality.,olf;longitudinally extending thin walled tubular ..ele ments, eachcomprising elongatedstructural filaments 31 of strong tensile materialcoated with a hardened adhesive substance and disposed in helicalformation to resist, and at a zonesubject to, said stresses, saidelements being bonded together by a hardened adhesive substance andextending along at least a substantial portion of said head.

12. A racket frame having a curvilinear head portion including at leastone elongated textile structural tube with filaments disposed diagonallyto the longitudinal axis thereof in combination with a separatestructural layer comprising a multitude of small, elongated tensileelements designed to resist longitudinal flexural stresses, saidfilaments and said elements being at a zone subject to said stresses andbeing coated and bonded together with an adhesive substance, and saidtube being designed to resist torsional and shearing stresses to whichsaid head is sub- 'ected.

] 13. A racket frame having a curvilinear head portion subject toshearing and torsional stresses and including at least one elongatedstructural textile tubular element formed with elongated structuraltensile laments at a zone subject to said stresses and disposed inhelical formation and a plurality of small, elongated structural tensilefilaments grouped within said element, the various laments being bondedtogether by a hardened adhesive substance and at least some of saidfilaments being so held in tensioned condition.

'- 14. A racket frame having a curvilinear head portion and including atleast one non-metallic, light-weight, longitudinally extending coreportion enclosed by elongated structural tensile filaments disposed inhelical tubular formation at a zone subject to shearing and torsion withlarnents crossing each other in opposite diagonal directions, said coreportion and said filaments being bonded together by a hardened adhesivesubstance.

15. A racket frame having a curvilinear head portion designed to holdunder pressure tight Stringing vulnerable to abrasion and including aplurality of longitudinally disposed structural braided tubes includingstrong elongated tensile filaments, said tubes having substantiallynon-abrasive material interposed between them designed to receiveStringing holes and support said Stringing and said filaments beingbonded together and to said material by a hardened adhesive substance.

16. A racket frame having Ka curvilinear head portion with an inturnedarch in its outer extremity designed to spring inward of the head whenthe frame is strung and in play and a highly resilient, spring-like,arched lamination bonded with an adhesive substance to the soit of saidinturned arch, said lamination having a plurality of small projectingpoints formed therewith as an integral part thereof which project intosaid frame in such manner that as said inturned arch springs inward thegrip of said points and their pressure into said frame is increased. 17.A racket frame having a curvilinear head portion subject to torsionaland shearing stresses in addition to exural stressing and includingopposed longitudinally extending structural laminations disposed at azone subject to said stresses comprising braided tubular elements formedwith strong elongated structural tensile filaments v`in` braidedformation and containing other strong longiudinally disposed structuraltensile filaments therein, said laments being coated and bonded togetherby a hardened *adhesive substance.

' glia/"A racket frame including filaments of material offliigh tensilestrength, including glass, extending conltinuously the entire length ofthe frame and under tennsion and with the opposed ends of said filamentsterminating in the handle end of the -frame and with both the opposedends of the laments held with the same equally drawn tension by ahardened adhesive substance.

19. A racket frame including at least one lamination reinforcing thesides of the head portion along its inner perimeter and substantiallyspaced away from the neutral axis of the frame and terminating ascantilevers with the opposed ends curving toward each other andterminating in the outer end of the racket head in combination with,abutting against the soit of, and serving to help support, an inturnedarch formed between same and tending to spring inward of the head withstring pressure.

20. A racket frame including laminations reinforcing the sides of thehead portion for at least a substantial length thereof along its innerperimeter and substantially spaced away from the neutral axis of theframe and terminating as cantilevers with opposed ends curving towardeach other and terminating in the outer end of the racket head incombination with, abutting against the soiiit of, and serving to helpsupport, an inturned arch formed between same and tending to springinward of the head with string pressure.

2l. A racket frame including cantilever portions in the head framing andterminating in the outer end and on the inner perimeter thereof, saidcantilever portions including material of substantially higher tensilestrength bonded to the tension side thereof and in combination with aninterposed inturned arch which tends to spring inward of the head withstring pressure.

22. A racket frame including cantilever portions in the head framing andterminating in spaced apart relation in the outer end thereof andsubstantially inward of the head in relation to the neutral axis of saidframe, said portions -being under tension so that their outerterminating ends normally tend to spring outward of the head incornbination with and serving to help support an inturned arch extendingbetween same and tending to spring inward of the head with stringpressure.

23. A racket frame including cantilever portions in the head framing andterminating in spaced apart relation in the outer end thereof and alongits inner side, said portions being reinforced on their tension sidewith material of substantially higher tensile strength and said materialalso forming a lamination of the frame spanning the gap between theouter terminal ends of said portions and in combination with an inturnedarch spanning between said cantilever portions and tending to springinward of the head with string pressure.

24. A racket frame having a curvilinear head portion subject totorsional, shearing and flexural stresses and including at least onetubular element formed with lbraided tensile filaments extendingsubstantially around the head and forming a container for a multitude oftensile laments disposed therein, the various la'ments being held by ahardened adhesive.

25. A racket frame including in the outer half of the head opposed humpson the faces of the frame with at least the greater portion of the peakof the hump disposed outward frorn the central transverse axis of thehead.

26. A racket frame subject to extreme torsional, ilexural, shearing anddelaminating stresses and including longitudinally extending laminationsdisposed at a zone subject to such stresses with their opposed facesadhesively joined together and having at least some of the sojoinedlaminations cross-bonded together diagonally across their edges byelongated glass filaments extending in helical formation as asubstantial structural element of said frame and coated, reinforced andbonded to said edges by a hardened adhesive substance.

References Cited in the le of this patent UNITED STATES PATENTS 823,028Brown June 12, 1906 1,532,991 De Meza Apr. 7, 1925 1,621,746 Morten Mar.22, 1927 1,637,583 Norton Aug. 2, 1927 1,921,616 Hall Aug. 8, 1933(Other references on following page) 33 UNITED STATES PATENTS RobinsonOct. 10, 1933 Nash Nov. 27, 1934 Davis Oct. 11, 1938 Le Compte et a1Nov. 12, 1940 Le Compte May 5, 1942 Hall May 12, 1942 Andreef Nov. 30,1943 Geerlings et al. Mar. 5, 1946 Rheinfrank Ian. 14, 1947 CollinsSept. 30, 1947 Rodgers etal. Oct. 30, 1951 34 Francis July 8, 1952Robinson Jan. 27, 1953 FOREIGN PATENTS Australia Aug. 10, 19.01 GreatBritain Nov. 24, 1924 France Apr. 28, 1928 Great Britain Oct. 18, 1928France Nov. 5, 1930 Australia Apr. 11, 1934 Australia May 4, 1938 GreatBritain Feb. 7, 1947 Great Britain Aug. 3, 1949

